Device for measurement of air humidity

FIELD: measurement equipment.

SUBSTANCE: device for measurement of air humidity comprises capacitance sensor of humidity (2), resistive temperature sensor (14), reference stable capacitor (20), high-resistance precision resistor (11), relay (13), the first and second normally closed contacts of relay (6, 22), the first and second normally open contacts of relay (7, 23), low-resistance precision resistor (12), reference high-precision resistor (21), AC voltage generator (1), line of AC voltage supply (8), metres of level of output signal from AC voltage amplifiers in capacitance sensor of humidity and resistive sensor of temperature (3, 4), source of relay supply (5), line of relay control (9), registrator (10), signal lines (15, 16), amplifiers of AC voltage of capacitance humidity sensor and resistive temperature sensor (17, 18), functional unit (19).

EFFECT: higher accuracy of air humidity measurement.

2 cl, 1 dwg

 

The invention relates to process control, nuclear power plants (NPP), in particular, to control humidity in the boxes for placing the pipelines of the main circulation circuit, and the humidity of the air in thermal insulation of piping and in the amount of trays reactor that uses water coolant.

It is known device [1], consisting of a power supply, a generator of electromagnetic radiation, a sound recording unit and the humidity sensor, made in the form of capacitive transformer. Primary plate capacitive transformer is a transmitting antenna connected to a generator for irradiating the sample, and the secondary plate is a receiving antenna, connected to the amplifying and recording unit. Between the primary and secondary plates placed zero plate. The sensor plates are placed in a plane parallel to the sample surface.

The device operation is based on the principle of registration of the induced potential of the electrical double layer of the particles containing sorbed moisture when exposed to electromagnetic radiation of ultrasonic frequency. The magnitude of the induced potential is experimental dependence on moisture content.

The disadvantage of the mouth of the STS is the lack of technical means to control the temperature of the investigated material which reduces the accuracy of measurement of the moisture content of the material and increases the accuracy of its determination. In addition, the technical implementation of the device prevents the introduction of its nuclear power plants as in conditions of high temperatures and exposure to radiation of the electronic equipment to be placed in the immediate vicinity of the humidity sensor becomes inoperative.

The closest to the technical nature of the claimed device is a device for measuring humidity in the patent of the Russian Federation [6]. The device provides a measurement of relative humidity by recording the changes in electrical capacitance of the humidity sensor due to the diffusion of water molecules in a special absorbing film capacitor [2], taking into account air temperature at the test point. Implementation of temperature control is performed using a resistive temperature sensor, placed in the immediate vicinity of the capacitive humidity sensor [3, 4, 5]. Resistive temperature sensor connected to the electronic Converter operating at a constant current, using a three - or four-wire line. Approval of the capacitive humidity sensor with signal line is implemented using a matching transformer, providing the opportunity to post capacitive is a moisture sensor resistive temperature sensor with electronic transducers at a distance up to 100÷150 m

The disadvantages of the known device should include a lack of sensitivity, as the relative humidity depends on the parameters of the matching transformer, which in conditions of high temperatures and exposure to radiation can vary widely, which in turn, increases the error in the measurement of relative humidity, as well as the high complexity and cost of the device due to the use of readnotify electronic converters and a large number of wires, the signal lines.

To eliminate these disadvantages, a device for measuring the humidity of air containing capacitive humidity sensor, resistive sensor, a generator of alternating voltage, the amplifier AC voltage, an electronic transducer resistance of a resistive temperature sensor into a voltage (current)to the input of which by means of a signal line connected resistive temperature sensor, a level meter AC voltage, function block, the output of which is connected to the recorder, and the output of the generator AC voltage is connected by a line with one of the contacts of the capacitive humidity sensor, the second is ontact which is connected the primary winding of the matching transformer, the second end of which is connected by a line with a generator of alternating voltage and to the secondary winding of the matching transformer connected to the signal line, the second end of which is connected to the amplifier AC voltage, the amplifier output AC voltage connected to the input level meter AC voltage, the output of which is connected to one of inputs of the functional block, the second input of the functional block is connected to the output e of the inverter resistance of a resistive temperature sensor into a voltage (current), relay, change-over relay contacts, the reference capacitor, the reference resistance is invited to:

- relay, which is using the line control relay connected to a power source relay;

first normalnotorowy relay contact connected to the second contact of the capacitive humidity sensor;

first normalisatie relay contact connected to the second contact stable reference capacitor;

second normalnotorowy relay contact connected to the second contact of the resistive temperature sensor;

second normalisatie relay contact connected to the second contact of the reference precision resistor;

to the second contact of the capacitive humidity sensor through the first normalnotorowy relay contact on the deleted first contact low-impedance precision resistor;

the second contact low-impedance precision resistor to connect the supply line AC voltage AC voltage generators;

- contact connection of low-resistance precision resistor and a capacitive humidity sensor, connect the signal line;

the second end of the signal line connected to the input terminals of the amplifier AC voltage of the capacitive humidity sensor;

the resistance value of the low resistance precision resistor to provide not less than 100÷200 times smaller than the module of the impedance of the capacitive humidity sensor and is equal to the wave impedance of the signal line amplifier to the AC voltage of the capacitive humidity sensor;

the generator output AC voltage, connect the supply line AC voltage to the first contact of the capacitive humidity sensor, with the first contact stable reference capacitor and the first contact resistance precision resistor;

the second contact resistance precision resistor connected with the first contact resistive temperature sensor, and the first contact of the reference precision resistor;

the second contact resistive temperature sensor through the second normalnotorowy relay contact to connect the supply line AC voltage with a gene is by ATOR AC voltage;

- contact connection of high resistance precision resistor, a resistive temperature sensor and the reference precision resistor to connect the signal line;

the second end of the signal line connected to the input terminals of the amplifier AC voltage resistive temperature sensor;

the resistance value of a resistive temperature sensor to provide at least 100-200 times less resistance high resistance precision resistor and is equal to the wave impedance of the signal line amplifier to AC voltage of a resistive temperature sensor;

the amplifier output AC voltage of a resistive temperature sensor be connected to the input level meter the output signal of the amplifier AC voltage resistive temperature sensor;

the second input of the functional unit to be connected to the output meter the output level of the amplifier AC voltage resistive temperature sensor.

In the particular case execution device is offered in the measurement channels of the capacitive humidity sensor and a resistive temperature sensor to apply the same type of uniform amps AC voltage and measuring the output level of the amplifiers AC voltage.

The drawing shows a structural with the EMA proposed device, where the following notation: 1 - AC voltage generator; 2 - capacitive humidity sensor (CWith); 3 - meter level of the output signal of the amplifier AC voltage of the capacitive humidity sensor; 4 - meter level of the output signal of the amplifier AC voltage resistive temperature sensor; 5 - power supply relay; 6 - first normalnotorowy relay contact; 7 - first normalisatie relay contact; 8 - supply line AC voltage; 9 - line control relay; 10 Registrar; 11 - high resistance precision resistor (Rq2); 12 - low-impedance precision resistor (Rq1); 13 - relay; 14 - resistive temperature sensor (RT); 15 - signal line; 16 - signal line; 17 - power AC voltage of the capacitive humidity sensor; 18 - amp AC voltage resistive temperature sensor; 19 - functional unit; 20 - stable reference capacitor (CE); 21 - reference precision resistor (RTE); 22 - second normalnotorowy relay contact; 23 - second normalisatie relay contact.

Device for measuring humidity contains a capacitive humidity sensor (CWith) 2, a resistive temperature sensor (RT) 14, a stable reference capacitor (CE) 20 high precision resistor (Rq2) 11, the relay 13, p is pout normalnotorowy relay contact 6, first normalisatie relay contact 7, the second normalnotorowy relay contact 22, the second normalisatie relay contact 23, a low-impedance precision resistor (Rq1) 12, the reference precision resistor (RTE) 21, AC voltage generator 1, the supply line AC voltage 8.

The output of the generator AC voltage 1 is connected by a supply line AC voltage 8 with the first contact of the capacitive humidity sensor 2, the first contact stable reference capacitor 20 and the first contact resistance precision resistor 11. The second contact of the capacitive humidity sensor 2 through the first normalnotorowy relay contact 6 is connected to a low-resistance precision resistor 12. The second contact low-impedance precision resistor 12 is connected by a supply line AC voltage 8 to the generator AC voltage 1. First normalisatie relay contact 7 is connected to the second contact stable reference capacitor 20. The second contact resistance precision resistor 11 is connected to the first contact of a resistive temperature sensor 14 and the first contact of the reference precision resistor 21. The second contact resistive temperature sensor 14 through the second normalnotorowy relay contact 22 is connected by a supply line AC voltage 8 with generator the AC voltage 1. Second normalisatie relay contact 23 connected to the second contact of the reference precision resistor 21.

Capacitive humidity sensor (CWith) 2 is used to measure the relative humidity (φ). The capacitance of the capacitive humidity sensor is ~30% of initial value when the relative humidity from 0 to 100%.

Resistive temperature sensor 14 is used to measure air temperature (T). As a resistive temperature sensor 14 is used thermal resistance. The change in resistance value of a resistive temperature sensor is ~40% from the original value when the temperature changes from 0 to 100°C.

AC voltage generator 1 is designed to supply the capacitive humidity sensor 2 and a resistive temperature sensor 14. AC voltage generator 1 generates harmonic AC voltage with frequency f and amplitude of the IG. The frequency f is selected as 1/2πfWith<<Ra, where CWiththe capacitance of the capacitive humidity sensor 2 (pF); Ra - resistance (insulation resistance) of the capacitive humidity sensor 2 (Ω). The frequency f is chosen in the range from 16 to 50 kHz.

The reference precision resistor (RTE) 21 is used in test mode channel availability measurement the Oia resistive temperature sensor 14. The value of the reference precision resistor (RTE) 21 is chosen equal to the resistance value of a resistive temperature sensor 14 at any given temperature (Tass, °C).

Reference stable capacitor (CE) 20 is used in test mode performance measurement channel capacitive humidity sensor 2. The value of the stable reference capacitor (CE) 20 is selected on the basis of the set value (Tass, °C) and a given value of relative humidity (φass, %), calculated by the formula (1).

Low-impedance precision resistor (Rq1) 12 is designed to generate an alternating voltage in the measurement channel of the capacitive humidity sensor 2, is proportional to the capacitance value of the capacitive humidity sensor 2. The resistance of the low resistance precision resistor (Rq1) 12 is selected Rq1<|XC|, where |XWith|=1/2πfCC- the module of the impedance of the capacitive humidity sensor 2. The alternating voltage U at the output of the generator AC voltage 1 creates an electrical circuit composed of a capacitive humidity sensor 2 and the low-impedance precision resistor 12, the current ICequal to IWith=IG/(XWith+Rq1). Taking into account the required measurement accuracy (0,5÷1,0%), the resistance of the low resistance precision what about the resistor 12 must be not less than 100÷200 times smaller than the module of the impedance of the capacitive humidity sensor 2, and the current ICis determined by the expression IWith=IG/XWith. Output AC voltage measurement channel capacitive humidity sensor, is equal to the voltage drop across the resistance of the low resistance precision resistor (Rq1) 12, is determined by the expression UWith=IC·Rq1=IG·Rq1·j2πfCCand linearly associated with the measured parameter is the capacitance of the capacitive humidity sensor 2.

High resistance precision resistor (Rq2) 11 is designed to generate an alternating voltage in the measurement channel of a resistive temperature sensor, proportional to the resistance value of a resistive temperature sensor 14. The resistance of the high resistance precision resistor (Rq2) 11 is selected Rq2>RTwhere RTthe resistance value of a resistive temperature sensor 14. The alternating voltage U at the output of the generator AC voltage 1 creates an electrical circuit composed of a high resistance precision resistor 11 and a resistive temperature sensor 14, the current ITequal to IT=IG/(Rq2+RT). Taking into account the required measurement accuracy (0,5÷1,0%), the resistance of the high resistance precision resistor 11 should be not less than 100÷200 times greater than the resistance of a resistive temperature sensor 14, and the current ITdetermined the expression is I T=IG/Rq2. Output AC voltage measurement channel resistive temperature sensor 14, is equal to the voltage drop across the resistance of a resistive temperature sensor (RT) 14, is determined by the expression UT=IT·RT=IG·RT/Rq2and linearly associated with the measured parameter is the resistance of a resistive temperature sensor 14.

Relay 13 connects a stable reference capacitor (CE) 20 and the reference precision resistor (RTE) 21 in the circuit for measuring capacitance of a capacitive humidity sensor 2 and the resistance of the resistive temperature sensor 14, respectively, in the test mode functionality.

First normalnotorowy relay contact 6 is provided to connect the second contact of the capacitive humidity sensor 2 and the low-impedance precision resistor (Rq112 channel capacitive humidity sensor 2.

Second normalnotorowy relay contact 22 connects the second contact resistive temperature sensor (RT) 14 to supply an alternating voltage 8 to the generator AC voltage 1 channel measuring resistive temperature sensor (RT) 14.

First normalisatie relay contact 7 is provided to connect the second contact is stable reference capacitor (CE) 20 with the bottom of omnem precision resistor (Rq 1) 12 mode to verify that the measurement channel of the capacitive humidity sensor 2.

Second normalisatie relay contact 23 connects the second contact of the reference precision resistor (RTE) 21 to supply an alternating voltage 8 to the generator AC voltage 1 mode test channel measurement resistive temperature sensor (RT) 14.

Supply line AC voltage 8 provides a supply of alternating voltage with frequency f and amplitude of the IG output from the generator AC voltage 1 circuit of the channel measurement of the capacitive humidity sensor and a measurement channel of a resistive temperature sensor. Type of supply line AC voltage 8 (cable with characteristic impedance ρl=50 Ohms) is selected from the transmission conditions without loss voltage AC voltage with frequency f and amplitude of the IG output AC voltage generators 1 and optimization types of signal lines of the device.

Device for measuring the humidity of the air also contains a meter level output signal of the amplifier AC voltage of the capacitive humidity sensor 3, the level meter output signal of the amplifier AC voltage resistive temperature sensor 4, the power source relay 5, the control line relay 9, the Registrar 0, the signal line 15, the signal line 16, the amplifier AC voltage of the capacitive humidity sensor 17, the amplifier AC voltage resistive temperature sensor 18, the functional block 19.

Relay 13 via the control line relay 9 is connected to the power source relay 5. Contact connect low-impedance precision resistor 12 and the capacitive humidity sensor 2 is connected a signal line 15. The second end of the signal line 15 is connected to the input terminals of the amplifier AC voltage of the capacitive humidity sensor 17. Contact-connection of high resistance precision resistor 11, a resistive temperature sensor 14 and the reference precision resistor 21 is connected a signal line 16. The second end of the signal line 16 is connected to the input terminals of the amplifier AC voltage resistive temperature sensor 18. The amplifier output AC voltage of the capacitive humidity sensor 17 is connected to the input level meter the output signal of the amplifier AC voltage of the capacitive humidity sensor 3. The amplifier output AC voltage of a resistive temperature sensor 18 is connected to the input level meter the output signal of the amplifier AC voltage resistive temperature sensor 4. The meter output level of the output signal of the amplifier AC n the voltage of the capacitive humidity sensor 3 is connected to one of inputs of the functional block 19. Second input of the functional block 19 is connected to the output meter the output level of the amplifier AC voltage resistive temperature sensor 4. The output of the function block 19 is connected to the recorder 10.

The power source relay 5 generates a voltage for operation of the relay 13.

The line control relay 9 provides a voltage on the relay 13 from the power source relay 5. The line type control relay 9 two - wire cable, twisted pair.

Power AC voltage of the capacitive humidity sensor 17 generates an output AC voltage. The magnitude of the AC voltage at the amplifier output AC voltage of the capacitive humidity sensor 17 is proportional to the capacitance value of the capacitive humidity sensor 2.

Power AC voltage resistive temperature sensor 18 generates an output AC voltage. The magnitude of the AC voltage at the amplifier output AC voltage of a resistive temperature sensor 18 is proportional to the resistance value of a resistive temperature sensor 14.

Measuring the output level of the amplifier AC voltage of the capacitive humidity sensor 3 generates a constant output voltage. The value of DC voltage on the output meter the output level of the amplifier changes the nogo voltage of the capacitive humidity sensor 3 is proportional to the capacitance value of the capacitive humidity sensor 2.

Measuring the output level of the amplifier AC voltage resistive temperature sensor 4 generates an output DC voltage. The value of DC voltage on the output meter the output level of the amplifier AC voltage resistive temperature sensor 4 is proportional to the resistance value of a resistive temperature sensor 14.

Functional block 19 is designed to correct the readings of relative humidity φ given temperature T. the Functional block 19 performs the operation of calculating the relative humidity φ by solving the equation:

where F is a known function of communication between the containerWithcapacitive humidity sensor 2, the air temperature T and relative humidity φ.

The recorder 10 records the relative humidity φ.

The signal line 15 provides a supply of AC output voltage UCchannel measurement of the capacitive humidity sensor, is equal to the voltage drop across the resistance of the low resistance precision resistor (Rq1) 12, to the input terminals of the amplifier AC voltage of the capacitive humidity sensor 17. Type signal line 15 (cable with characteristic impedance ρl=50 Ohms) is selected from the transmission conditions without loss of alternating n the voltage U C. When connecting the signal line 15 parallel to the resistance of the low resistance precision resistor (Rq1) 12 is connected impedance of the signal line 15. Condition loss-free transmission of alternating voltage UCis the impedance matching of the signal line 15, the input resistance of the amplifier AC voltage of the capacitive humidity sensor 17 and the resistance of the low resistance precision resistor (Rq1) 12. In General, the attenuation of the signal line 15 apmismatched parameters is determined by the formula [7]:

where UoUI- output voltage and the input signal line 15, respectively, In;

z0- impedance of the signal source (in our case z0=Rq1for channel measurement of the capacitive humidity sensor), Ohm;

zBcomplex input impedance of the amplifier AC voltage of the capacitive humidity sensor 17, Ohm;

zl- complex (wave) cable resistance, Ohm;

l - cable length, m;

α is the coefficient of damping in the cable, defined by the expression

where R is linear cable resistance, Ohm/m;

L - inductance cable, GN/m;

C - linear capacitance of the cable, f/m;

G linear conductance of the insulation, 1/Ohm·m;

γ - coefficient distribution of cable, defined by the expression:

The parameters R, L, C, G are functions of frequency [7]. As can be seen from (3), with the concurrence of the parameters, i.e. when performing equality

the attenuation in the line αpis determined by the expression:

Value and, as a rule, insignificant for the frequency range up to 100 kHz. For example, RF coaxial cable, type RK-50-24-15 at the frequency f=100 kHz is the attenuation coefficientIf the length of the signal line 200 m attitude module voltages at the input and output of the signal line 15 is:

For the case of (8) losses (3%) will be constant and easily accounted for in the General conversion factor. Condition (8) is strictly may be performed for the measurement channel of the capacitive humidity sensor, since the resistance Rq1constant and chosen to be equal to the wave resistance of the cable signal line 15. Thus, the output AC voltage UCchannel measurement of the capacitive humidity sensor, is equal to the voltage drop across the resistance Rq1transmitted on the signal line 15 to the input of the amplifier AC voltage of the capacitive humidity sensor 17, linearly associated with a change in jemym parameter the capacitance of the capacitive humidity sensor 2.

The signal line 16 provides a supply of AC output voltage UTchannel measurement resistive temperature sensor is equal to the voltage drop across the resistance of a resistive temperature sensor (RT) 14, to the input terminals of the amplifier AC voltage resistive temperature sensor 18. Type signal line 16 (cable with characteristic impedance ρl=50 Ohms) is selected from the transmission conditions without loss of alternating voltage UT. When connecting the signal line 16 in parallel with the resistance of a resistive temperature sensor (RT) 14 is connected impedance of the signal line 16. Condition loss-free transmission of alternating voltage UTis the impedance matching of the signal line 16, the input resistance of the amplifier AC voltage resistive temperature sensor 18 and the resistance of a resistive temperature sensor (RT) 14. In General, the attenuation of the signal line 16 apmismatched parameters [7] is defined by the formula (2)÷(7), in which channel measurement resistive temperature sensor (RT) 14:

z0- impedance of the signal source (in our case z0=RTfor channel measurement resistive temperature sensor), Ohm;

zB complex input impedance of the amplifier AC voltage resistive temperature sensor 18, Ohm;

zl- complex (wave) cable resistance, Ohm.

For channel measurement resistive temperature sensor resistance value RTwill change with changing temperature. Therefore, exact agreement with the wave impedance of the signal line 16 in the whole range of temperature changes cannot be made. Rate if any additional errors that will cause.

Let the value of RTdepends on the temperature according to the law:

where R0the resistance value of a resistive temperature sensor (RT) 14 (resistive) at a temperature T0, Ohm;

β is the temperature coefficient resistive temperature sensor (RT) 14 (resistive), 1/Ohm·°C.

Let the range of temperature change ΔT=Tmax-T0is ΔT=100°C. Then the maximum resistance value of a resistive temperature sensor (RT) 14 (resistive) will be: RmaxT=1.4R0when β≅4·10-3Ω-1·°C-l(platinum resistance thermal Converter).

We choose a value of R0equal to the wave resistance of the signal if the AI 16

As follows from formula (9), due to the change in resistance RTwill be a mismatch signal line 16 to the output impedance of signal source that will result in an additional increase of damping on the value of the

In the formula (11) is denoted by: z0=RT; zIn=zll.

Estimate the maximum value of the second member (11) when RT=RmaxT. Obviously it will be equal to:

.

Full maximum attenuation in the signal line 16 at a length of 200 m will be.

The ratio of the output voltage of the signal line 16 to the input voltage signal line 16 decreases to values

This leads to a maximum not take into account the error of measurement of the resistance of the resistive temperature sensor (RT) 14 (resistive) ≈1%, which is quite acceptable when measuring the humidity parameters. Thus, the output AC voltage UTchannel measurement resistive temperature sensor is equal to the voltage drop across the resistance RTtransmitted on the signal line 16 to the input of the amplifier AC voltage resistive temperature sensor 18, inano associated with the measured parameter, the resistance of a resistive temperature sensor (RT) 14.

Further, in the particular case of the measuring channels of the capacitive humidity sensor and a resistive temperature sensor uses the same type of uniform amps AC voltage and measuring the output level of the amplifiers AC voltage.

Note the advantages of the device:

As can be seen from the diagram of the device (see drawing), for connection of a capacitive humidity sensor 2 to the amplifier AC voltage of the capacitive humidity sensor 17 and a resistive temperature sensor 14 to the amplifier AC voltage resistive temperature sensor 18 required three shielded signal lines 8, 15, 16 and one two-wire line to the relay 9. This removal of the signal from the resistive temperature sensor 14 (thermal resistance) is equivalent to the method of removal using a four-wire line.

Measuring the parameters of the capacitive humidity sensor 2 and a resistive temperature sensor 14 is performed in the device with alternating current of one frequency. This allows you to apply the same type of amplifiers and level meters voltage measurement channels of the capacitive humidity sensor and a resistive temperature sensor.

Matching impedances of the signal lines 15, 16 measurement channels capacitive touchpad is as humidity and a resistive temperature sensor, the input impedance of the amplifiers AC voltage of the capacitive humidity sensor 17 and a resistive temperature sensor 18, the resistance value of the low resistance precision resistor 12 in the circuit of the capacitive humidity sensor 2 and the resistance value of a resistive temperature sensor 14 allows you to post the moisture sensors and temperature (working in conditions of high temperatures and exposure to radiation) to a distance of 100-200 m from the electronic signal transducers (work in conditions of high temperatures and exposure to radiation) and placed in areas serviced areas with low background radiation and normal climatic conditions, allowing the use of devices for nuclear power plants.

The device provides remote health checks of measurement channels of the capacitive humidity sensor and a resistive temperature sensor.

The device operates as follows.

When the supply voltage to the device AC voltage generator 1 generates in the circuit of the capacitive humidity sensor 2 low-impedance precision resistor 12 is an alternating voltage proportional to the capacitance value of the capacitive humidity sensor 2, as in the circuit of a resistive temperature sensor which measures 14 - AC voltage equal to the voltage drop across the resistive temperature sensor 14, is proportional to the resistance value of a resistive temperature sensor 14. The AC voltage signals of the measuring channels of the capacitive humidity sensor and a resistive temperature sensor is amplified in the amplifier AC voltage of the capacitive humidity sensor 17 and the amplifier AC voltage resistive temperature sensor 18, are detected at the meter level output signal of the amplifier AC voltage of the capacitive humidity sensor 3 and the level meter output signal of the amplifier AC voltage resistive temperature sensor 4 and the DC voltage received on the functional block 19, which calculates the relative humidity with respect to temperature of air at the test point. Relative humidity is recorded in the recorder 10.

The mode of the health check is carried out by applying voltage to the relay 13 from the power source relay 5 through the control line relay 9 in two ways: automatically or two times a day, as well as operative in manual mode. When the relay 13 of the first and second normalisatie relay contacts 6, 22 are switched to position the first and second normalgenerator contact is in the relay 7, 23, respectively. In the measurement channel of the capacitive humidity sensor is connected stable reference capacitor 20, and the channel measurement resistive temperature sensor is connected the reference precision resistor 21. Using the known dependence to relative humidity and temperature, with the required accuracy are controlled by the values of φass, % and Tass, °C and, thus, is the health score as the measuring channels of the capacitive humidity sensor and a resistive temperature sensor separately, and devices in General.

An example of a specific implementation of the device.

Device for measuring humidity implemented in the device IVTV-2. The device consists of a sensor and block amplifiers-converters (epmo). In the sensor housing made of stainless steel 12X18H10T posted (see drawing) capacitive humidity sensor (CWith) type 2 NS with a range of changes in the capacitance from 397 to 520 pF when changing the relative humidity from 0 to 100%, respectively, of the relay type RACK, high resistance precision resistor 11 type S2-29V-0,125 (Rq2=20 kω), low-impedance precision resistor 12 type S2-29V-0,125 (Rq1=to 49.9 Ohm)resistive temperature sensor type 14 50P (Rtwith the range of resistance change from 50 to 70 Ohms when the temperature of the air is t 0 to 100°C, accordingly, the reference precision resistor 21 type S2-29V-0,125 (RTE=54,9 Om corresponds to Tass=25°C), stable reference capacitor (CE) 20 type To 10-73-1B (CE=510 pF corresponds to φass=85% at Tass=25°C). Dimensions of sensor: ⌀ 50×160 mm Weight sensor does not exceed 1.0 kg

Block amplifiers, converters consists of a generator of alternating voltage 1 (AC voltage with frequency f=16 kHz and amplitude IG=1.0), measuring the output level of the amplifier AC voltage of the capacitive humidity sensor 3, level meter output signal of the amplifier AC voltage resistive temperature sensor 4, the power source relay 5 type PSM112, Registrar of 10 based single Board computer Athena in the standard PC-104, amplifier AC voltage of the capacitive humidity sensor 17, the amplifier AC voltage resistive temperature sensor 18, the functional block 19. The dimensions of the BUP: 300×153×370 mm Weight BUP does not exceed 8,0 kg Sensor is connected with BUP through supply line AC voltage 8, line control relay 9, the signal line (measurement channel capacitive humidity sensor) 15 and the signal line (channel measurement resistive temperature sensor) 16.

The device is powered by the mains AC voltage is (220+22, 220-33), frequency (50±1) Hz. Power consumption does not exceed 50 watts.

The technical result consists in increasing the accuracy of measurement of air humidity.

Sources of information

1. Patent of the Russian Federation No. 2078335 from 27 April 1997 "Method for measuring moisture content of materials and device for its implementation", Trufanov V.N.; Poles BS; Gamow M.I.; Semitico GI; Slavgorod NI; Trufanov AV; Angelevski IB

2. Wigler, Sensors. - M.: Mir, 1989.

3. Measurements of gaseous and liquid media in the operation of engineering equipment of buildings. The Handbook. - M.: stroiizdat, 1987.

4. Measuring transducers for temperature and humidity IPTV. Technical conditions. THE 4227-005-13282997-97. Gosstandart Ross, Unintended. Entered in the Register under No. 200/015990, 1997.

5. Measuring instruments approved for use in the Russian Federation. Description of approved types. Issue 14 (114). - M.: VNIIMS. 1997.

6. Patent of the Russian Federation No. 2184369 on June 27, 2002, "a Device for measuring the humidity of the air, Morozov, S.A., Kovtun, S., Okladnikov V.M.

7. The Belarusians NI, Gridnev I.I. Radio-frequency cables. - M.: Energy, 1973

1. Device for measuring humidity, including capacitive humidity sensor, resistive sensor, a generator of alternating voltage, function block, the relay, and the output of the function block poseiden the n to the Registrar, wherein the relay with a control line connected to the power source relays, generator output AC voltage is connected by a supply line AC voltage to the first contact of the capacitive humidity sensor, with the first contact stable reference capacitor and the first contact resistance precision resistor, to the second contact of the capacitive humidity sensor through the first normally closed contact of the relay is connected to a low-resistance precision resistor connected to the supply line of the AC voltage with the alternating voltage, the second contact stable reference capacitor connected to the first normally open relay contact, a second contact resistance precision resistor connected to the first contact resistive temperature sensor, and the first contact the reference precision resistor, a second contact resistive temperature sensor through the second normally closed contact of the relay is connected by a supply line AC voltage with the alternating voltage to the second contact of the reference precision resistor connected to the second normally open contact of the relay, the contacts of the connection of the capacitive humidity sensor and a low-impedance precision resistor connected to the signal line, the other end of which is connected to the input terminals of the amplifier AC voltage of the capacitive humidity sensor, moreover, the resistance value of the low resistance precision resistor is not less than 100÷200 times smaller than the module of the impedance of the capacitive humidity sensor and is equal to the impedance specified signal line, is connected to the input terminals of the amplifier AC voltage of the capacitive humidity sensor, contact-connection of high resistance precision resistor, a resistive temperature sensor and the reference precision resistor connected to the signal line, the second end of which is connected to the input terminals of the amplifier AC voltage of a resistive temperature sensor, and the resistance value of a resistive temperature sensor is not less than 100÷200 times less resistance high resistance precision resistor and is equal to the wave impedance of the signal line connected to the input terminals of the amplifier AC voltage of a resistive temperature sensor, the amplifier output AC voltage of the capacitive humidity sensor connected to the input level meter the output signal of the amplifier AC voltage of the capacitive humidity sensor, the amplifier output AC voltage of a resistive temperature sensor connected to the input level meter the output signal of the amplifier AC voltage of a resistive temperature sensor, in the course of measuring the output level of the amplifier AC voltage of the capacitive humidity sensor is connected to one of inputs of the functional block, and the second input of the functional unit is connected to the output meter the output level of the amplifier AC voltage resistive temperature sensor.

2. The device according to claim 1, characterized in that the measuring channels of the capacitive humidity sensor and a resistive temperature sensor, apply the same type of uniform amps AC voltage and measuring the output level of the amplifiers AC voltage.



 

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SUBSTANCE: hygrometer includes cooling system, measuring chamber, temperature sensor, light source, photodetector, inlet and outlet manifolds, valves, pressure gauge, flowmeter and cooler. Cooling system includes flat groove recess parallel to the axis of the measuring chamber and the aperture thereover covered with shielding glass with light source above. According to the version 2, hygrometer comprises photodetector mounted together with light source. According to the version 3, hygrometer includes the second photodetector along the axis of the measuring chamber.

EFFECT: higher measurement accuracy of gas dew point and design simplification.

3 cl, 4 dwg

FIELD: analytical chemistry.

SUBSTANCE: method includes using static "electronic nose", whose matrix is formed from 2 weight-sensitive piezo-sensors, whose electrodes are modified by even application of film of acetone solutions of polyethylene glycol PEG-2000 and polyvinylpyrrolidone, and subjected to drying. Modified weight-sensitive piezo-sensors are fixed in holders on cover and put in bode of static "electronic nose". Completeness of removal of free solvents from films is controlled by constancy of fluctuations of weight-sensitive piezo-sensors, then sample of stock cube, dry bouillon or soup base is taken, heated, crushed thoroughly and mixed, placed into weighing bottle with polyurethane membrane on cover. Sample is kept in weighing bottle during 10-15 minutes. After saturation of gas phase with water vapours through polyurethane membrane sample of equilibrium gas phase is taken with 3-5 cm3 syringe, which is quickly injected into body of static "electronic nose". Frequency of fluctuations of weight-sensitive piezo-sensors is fixed, total analytic signal is formed in form of kinetic "visual print" and is compared with standards. Area of figure S"в.а" is calculated and humidity of sample ω % is determined using calibrating diagram drawn in coordinates S"в.а"=f (ω, wt %).

EFFECT: high expressiveness, reliability, accuracy, objectivity and simplicity of determining.

3 dwg

FIELD: food industry.

SUBSTANCE: method comprises grinding the dump specimen of the agent in the thermograph by heating that is accompanied by its drying, obtaining a temperature curve of the agent, and determining the concentration of water fractions from the temperature curve.

EFFECT: reduced time consumption and enhanced reliability.

1 dwg

FIELD: measuring equipment engineering.

SUBSTANCE: condensation hygrometer contains a layer of oxidized porous silicon on mono-crystalline substrate, a system of opposite-pin electrodes and metallic contacts to it. Pores in oxidized porous silicon have conical shape, expanding towards surface, while electrodes, isolated by oxide, are made of poly-silicon and are embedded into body of mono-crystalline substrate for whole thickness of porous layer.

EFFECT: provision of possible operation at high temperatures, increased sensitivity during operation at high temperatures, increased resistance to effect of high temperatures and thermo-cycling.

1 dwg

FIELD: measurement engineering.

SUBSTANCE: moisture is extracted from moisture-containing organic material, for example, from timber. Device is used which has pressure-tight chambers for removing moisture, carriages for loading organic materials, moisture collectors and heat lines. Weight of removed moisture in relation to weight of organic material is calculated.

EFFECT: reduced time of procedure; increased precision of testing.

3 cl, 5 dwg

FIELD: atomic power engineering; registration systems of leaks of the heating carrier of the 1-st loops of the reactor facilities of nuclear electric power plants.

SUBSTANCE: the invention is pertaining to the field of atomic power engineering and may be used in at the reactor installations with the water-to-water and water-graphite reactors, in particular, at a decompression of the 1-st loop. The registration system of leaks of the heating carrier of the 1-st loops of the reactor facilities of a nuclear electric power plant contains a block of the controlled rooms with equipment of the 1-st loop of the reactor installation connected through air ducts of exhaust ventilation with a block of the channels intended for measuring of relative humidity of the air in the controlled rooms, that includes a reference channel intended for measuring of relative humidity of outdoor air in the rooms with the measuring channels. Sensor units of measuring channels are connected to a control unit for recording and matching of the parameters of the relative humidity of the air in the controlled rooms and in the room with the measuring channels, each of which is made in the form of an expander, on one butt of which there is a branch pipe with a filtering tool connected with the air duct, and on the other butt there is a flange intended for mounting of a sensor. At that outside of the expander there is a cooling chamber. The invention allows to simplify the process of the control over the indications of the relative humidity of the air in the controlled rooms and to improve reliability of operation of the reactor installation by well-timed detection of a location and intensity of the leakage of the heating carrier.

EFFECT: the invention ensure simplified control over the indications of the relative humidity of the air in the controlled rooms, improved reliability of the reactor installation operation by well-timed detection of a location and intensity of the heating carrier leakage.

6 cl, 9 dwg

FIELD: hygrometers with bolometric heat sensitive member, stove or furnace using such hygrometer and method for controlling stove or furnace.

SUBSTANCE: hygrometer includes two static bolometric heat sensitive members for accurate detection of humidity value. Stove or furnace includes bolometric hygrometer secured to one side of bracket in air discharge opening for deflecting direction of air flow in order to detect humidity value at high accuracy in cooking chamber. Method for controlling operation mode of stove or furnace provides different periods of heat treatment of food products in package or without it.

EFFECT: enhanced accuracy of humidity measuring.

13 cl, 15 dwg

FIELD: measurement technology.

SUBSTANCE: electric insulating base, electric insulating substrate onto which moisture-sensitive coating is applied on the base of gelatin which has its external layer tanned, two plated electrodes which have contact surface to contact with moisture-sensitive coating on base of gelatin and measuring device connected to outputs of plated electrodes. Two clamping units are introduced into the device additionally. Any clamping unit intends for creating permanent pressure of corresponding plated electrode onto working surface of moisture-sensitive coating on base of gelatin. Layer of gelatin coating has uniform thickness. Contact surface of plated electrodes adjacent the moisture-sensitive gelatin-based coating is made to be oxidized and flat.

EFFECT: prolonged service life; higher stability of operation; increased moisture resistance.

5 cl, 1 dwg

The invention relates to techniques for measuring

FIELD: measurement technology.

SUBSTANCE: electric insulating base, electric insulating substrate onto which moisture-sensitive coating is applied on the base of gelatin which has its external layer tanned, two plated electrodes which have contact surface to contact with moisture-sensitive coating on base of gelatin and measuring device connected to outputs of plated electrodes. Two clamping units are introduced into the device additionally. Any clamping unit intends for creating permanent pressure of corresponding plated electrode onto working surface of moisture-sensitive coating on base of gelatin. Layer of gelatin coating has uniform thickness. Contact surface of plated electrodes adjacent the moisture-sensitive gelatin-based coating is made to be oxidized and flat.

EFFECT: prolonged service life; higher stability of operation; increased moisture resistance.

5 cl, 1 dwg

FIELD: hygrometers with bolometric heat sensitive member, stove or furnace using such hygrometer and method for controlling stove or furnace.

SUBSTANCE: hygrometer includes two static bolometric heat sensitive members for accurate detection of humidity value. Stove or furnace includes bolometric hygrometer secured to one side of bracket in air discharge opening for deflecting direction of air flow in order to detect humidity value at high accuracy in cooking chamber. Method for controlling operation mode of stove or furnace provides different periods of heat treatment of food products in package or without it.

EFFECT: enhanced accuracy of humidity measuring.

13 cl, 15 dwg

FIELD: atomic power engineering; registration systems of leaks of the heating carrier of the 1-st loops of the reactor facilities of nuclear electric power plants.

SUBSTANCE: the invention is pertaining to the field of atomic power engineering and may be used in at the reactor installations with the water-to-water and water-graphite reactors, in particular, at a decompression of the 1-st loop. The registration system of leaks of the heating carrier of the 1-st loops of the reactor facilities of a nuclear electric power plant contains a block of the controlled rooms with equipment of the 1-st loop of the reactor installation connected through air ducts of exhaust ventilation with a block of the channels intended for measuring of relative humidity of the air in the controlled rooms, that includes a reference channel intended for measuring of relative humidity of outdoor air in the rooms with the measuring channels. Sensor units of measuring channels are connected to a control unit for recording and matching of the parameters of the relative humidity of the air in the controlled rooms and in the room with the measuring channels, each of which is made in the form of an expander, on one butt of which there is a branch pipe with a filtering tool connected with the air duct, and on the other butt there is a flange intended for mounting of a sensor. At that outside of the expander there is a cooling chamber. The invention allows to simplify the process of the control over the indications of the relative humidity of the air in the controlled rooms and to improve reliability of operation of the reactor installation by well-timed detection of a location and intensity of the leakage of the heating carrier.

EFFECT: the invention ensure simplified control over the indications of the relative humidity of the air in the controlled rooms, improved reliability of the reactor installation operation by well-timed detection of a location and intensity of the heating carrier leakage.

6 cl, 9 dwg

FIELD: measurement engineering.

SUBSTANCE: moisture is extracted from moisture-containing organic material, for example, from timber. Device is used which has pressure-tight chambers for removing moisture, carriages for loading organic materials, moisture collectors and heat lines. Weight of removed moisture in relation to weight of organic material is calculated.

EFFECT: reduced time of procedure; increased precision of testing.

3 cl, 5 dwg

FIELD: measuring equipment engineering.

SUBSTANCE: condensation hygrometer contains a layer of oxidized porous silicon on mono-crystalline substrate, a system of opposite-pin electrodes and metallic contacts to it. Pores in oxidized porous silicon have conical shape, expanding towards surface, while electrodes, isolated by oxide, are made of poly-silicon and are embedded into body of mono-crystalline substrate for whole thickness of porous layer.

EFFECT: provision of possible operation at high temperatures, increased sensitivity during operation at high temperatures, increased resistance to effect of high temperatures and thermo-cycling.

1 dwg

FIELD: food industry.

SUBSTANCE: method comprises grinding the dump specimen of the agent in the thermograph by heating that is accompanied by its drying, obtaining a temperature curve of the agent, and determining the concentration of water fractions from the temperature curve.

EFFECT: reduced time consumption and enhanced reliability.

1 dwg

FIELD: analytical chemistry.

SUBSTANCE: method includes using static "electronic nose", whose matrix is formed from 2 weight-sensitive piezo-sensors, whose electrodes are modified by even application of film of acetone solutions of polyethylene glycol PEG-2000 and polyvinylpyrrolidone, and subjected to drying. Modified weight-sensitive piezo-sensors are fixed in holders on cover and put in bode of static "electronic nose". Completeness of removal of free solvents from films is controlled by constancy of fluctuations of weight-sensitive piezo-sensors, then sample of stock cube, dry bouillon or soup base is taken, heated, crushed thoroughly and mixed, placed into weighing bottle with polyurethane membrane on cover. Sample is kept in weighing bottle during 10-15 minutes. After saturation of gas phase with water vapours through polyurethane membrane sample of equilibrium gas phase is taken with 3-5 cm3 syringe, which is quickly injected into body of static "electronic nose". Frequency of fluctuations of weight-sensitive piezo-sensors is fixed, total analytic signal is formed in form of kinetic "visual print" and is compared with standards. Area of figure S"в.а" is calculated and humidity of sample ω % is determined using calibrating diagram drawn in coordinates S"в.а"=f (ω, wt %).

EFFECT: high expressiveness, reliability, accuracy, objectivity and simplicity of determining.

3 dwg

FIELD: physics.

SUBSTANCE: hygrometer includes cooling system, measuring chamber, temperature sensor, light source, photodetector, inlet and outlet manifolds, valves, pressure gauge, flowmeter and cooler. Cooling system includes flat groove recess parallel to the axis of the measuring chamber and the aperture thereover covered with shielding glass with light source above. According to the version 2, hygrometer comprises photodetector mounted together with light source. According to the version 3, hygrometer includes the second photodetector along the axis of the measuring chamber.

EFFECT: higher measurement accuracy of gas dew point and design simplification.

3 cl, 4 dwg

FIELD: physics, tests.

SUBSTANCE: invention is related to devices for testing of construction materials and may be used to detect moisture resistance of heat insulation materials of fibrous structure, in particular products of mineral wool. Device for moisture resistance testing of heat insulation fibrous material samples comprises untight chamber with detachable cover equipped with sources and controllers of water heating to boiling, inside of which there is a detachable meshy tray for installation of tested samples. Moreover, on detachable cover there is a standard instrument for detection of compressibility of fibrous heat insulation materials. Besides movable stem of standard instrument passes through detachable cover of untight chamber inside guide tube and rests on test sample via additionally introduced spatial frame, which eliminates distortions from effect of heat and moisture medium at sample in process of its moisture resistance testing, and on top and bottom of test sample, meshy gaskets are installed for even transfer of pressure to test sample.

EFFECT: development of device that has high efficiency in operation and improved authenticity of sample testing results.

5 cl, 1 dwg

FIELD: measurement equipment.

SUBSTANCE: device for measurement of air humidity comprises capacitance sensor of humidity (2), resistive temperature sensor (14), reference stable capacitor (20), high-resistance precision resistor (11), relay (13), the first and second normally closed contacts of relay (6, 22), the first and second normally open contacts of relay (7, 23), low-resistance precision resistor (12), reference high-precision resistor (21), AC voltage generator (1), line of AC voltage supply (8), metres of level of output signal from AC voltage amplifiers in capacitance sensor of humidity and resistive sensor of temperature (3, 4), source of relay supply (5), line of relay control (9), registrator (10), signal lines (15, 16), amplifiers of AC voltage of capacitance humidity sensor and resistive temperature sensor (17, 18), functional unit (19).

EFFECT: higher accuracy of air humidity measurement.

2 cl, 1 dwg

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