That the manometer correctly measured pressure, without distorting information, it needs to be checked regularly. At the same time it is almost impossible to determine correctness of indications by appearance of this device. To make check, verify its indications with the manometer which shows obviously exact indications, or calculate gas pressure then measure it by means of the manometer and compare indications.
It is required to you
- reference manometer and thermometer
Instruction
1. To check gas pressure in capacity, install the manometer sensor in it. For this purpose, as rules exist special unions. When the value is recorded, remove the manometer, and install the reference device on this place. Having compared indications of simple and reference manometers, check correctness of instrument readings. If instrument readings do not coincide with the reference manometer, adjust it that in identical conditions the manometers showed identical results.
2. For control on the case of the manometer adjusting bolts, as a rule, are provided. With the electronic manometer an algorithm of actions same, it is only necessary to consider that this device has lag effect therefore indications it is necessary to hold from 8 to 10 pages.
3. If there is no reference manometer, air correctness of indications of the manometer, previously having calculated pressure. For this purpose take a vessel of the known volume. Air is in it with an atmospheric pressure which can be measured by means of a barometer, and temperature is equal to room. Then, hermetically close a cylinder, and begin to heat it, controlling temperature and pressure which has to increase. Calculate pressure in a cylinder, having divided final temperature into initial. Then increase result by value of atmospheric pressure. P2=T2•P1/T1.
4. If indications of the manometer at this temperature do not coincide with calculated earlier, adjust it so that it showed so much how many it turned out when calculating. At performing calculations consider that temperature is taken in degrees Kelvin for what to degrees Celsius add number 273. Scales of manometers, as a rule, are graduated in kg/cm², calculation will be derivative in pascals, or millimeters of mercury therefore it is necessary to transfer its identical units of measure and only then to compare.