Made in: 2017
Hygrometer Psychrometric VIT-2 (VIT 2, VIT2)
Metrological checking is included in the device.
Specifications hygrometer psychrometric VIT-2:
The range of relative humidity,% 54% ... 90%, 40% ... 90%, 20% ... 90%
Temperature range humidity measurement, ° C 20 ° C. .. 23 ° C, 23 ° C. .. 26 ° C, 26 ° C. .. 40 ° C
Temperature measurement range, ° C 15 ° C. .. 40 ° C
Of full scale thermometer, ° C 0,2 ° C
Absolute error of thermometers including the introduction of corrections shall not exceed ± 0,2 ° C.
Limit the absolute error VIT 2 at aspiration of 0.5 to 1 m / s is shown in Table 1.
Overall dimensions, mm, not more - 325x120x50.
Weight, g, not more than - 350.
Hygrometer Psychrometric VIT 2 corresponds to the technical requirements specification and found fit for use.
Hygrometers VIT-2 to be checking the time of release from production, to use hygrometers be verification or calibration, depending on the application.
Calibration interval - not more than 2 years.
Safety requirements hygrometer VIT-2
When working with a hygrometer is prohibited:
readability hygrometer sharp blow as the installation and during operation;
wipe the thermometer scale and psychrometric chart solvents, acids and other similar fluids;
perenagrevat hygrometer thermometer more than 45 ° C. When overheating is destroyed tank thermometers.
Structure and function of the device psychrometer VIT-2
Hygrometer Psychrometric VIT-2 is a plastic base which carries two thermometers with scale psychrometric table, glass feeder. Tank thermometer labeled "moisturizing", moistened with water feeder with cambric or chiffon wick.
The method of measuring the relative humidity hygrometer psychrometric VIT-2 is based on the relationship between humidity and psychrometric difference - a difference reading "dry" and "wet" thermometers that are in thermodynamic equilibrium with the environment.
Remove the thermometer readings and after entering amendments to their testimony, to determine the difference between the readings of thermometers. Then, on the testimony of "dry" and the difference between the thermometer reading "dry" thermometer "wet" to determine the relative humidity of the air on a psychrometric table.
Operation hygrometer VIT-2
Clear evidence on the "dry" and "wetted" thermometer.
Determine the temperature on the thermometer up to 0,1 ° C by introducing amendments to the marked thermometer readings given in the passport for hygrometer VIT 2. Calculate the temperature difference on the "dry" and "wetted" thermometer. The amendments introduced by the algebraic addition.
In the absence of a passport amendments for readings of "dry" and "wetted" thermometer, calculate the correction of the linear interpolation of the two amendments that relate to temperatures between which lies a reading on the thermometer.
Determine the relative humidity of the air on a psychrometric table. The desired relative humidity is at the intersection of lines of temperature on the "dry" thermometer and the temperature difference on the "dry" and "wetted" thermometer.
In the absence of a table obtained by the temperature difference between "dry" and "wetted thermometer hygrometer psychrometric VIT-2 to determine the moisture, apply interpolation. In the absence of a table dry bulb temperature, to determine the moisture content of interpolation only for those parts of the psychrometric tables, which measure the temperature on the "dry" bulb by 1 ° C gives the relative humidity change by more than 1%. For the rest of the table temperature to "dry" bulb round up to the nearest table value by the rule of arithmetic rounding.
Example of determining the relative humidity of the interpolation (psychrometers HIT-2).
Determine the temperature in "dry" and "wetted" thermometer VIT-2, and the difference between these temperatures.
Take T = 22.4 with the difference in temperature (T c-T a) is: 22,4-16,3 = 6,1
Determine the relative humidity for a T = 22,4 ° C, which interpolate the value of the relative humidity on the table for T c from 22 to 23 ° C. With an increase in temperature of 1 ° C humidity increases by 2%, while increasing the temperature by 0,4 ° C humidity increases by 0,4 x2 = 0,8% 48 0.8 = 48.8.
Determine the relative humidity for a T = 22,4 ° C and T c-T a = 6,1 ° C, which interpolate the value of the relative humidity difference in the readings of 6.0 to 6,5 ° C. With an increase in T c-T y to 0,5 ° C relative humidity is reduced by 4%, and an increase in T c-T y to 0,1 ° C decreases relative humidity (0,1 x4, 0) = 0.5 0.8%.
Hence, humidity "fi" at 22.4 and T c-T a = 6,1 ° C is equal to 48,8-0,8 = 48%.