As nobody uses mercury barometers by means of which Torricelli conducted the experiments in life, they were succeeded by so-called aneroid barometers. But sometimes, after a call on a meteorological station, it turns out that their indications strongly differ from reference. Therefore when choosing a barometer it is necessary to consider its reliability, parameters of adjustment and quality of assembly.
It is required to you
- screw-driver, reference barometer
Instruction
1. When choosing the aneroid barometer first of all pay attention to the adjusting screw which is most often located on a back cover of the case of the device. If it is located not on one axis with the center of an opening under it, then it is possible to guarantee that the metal box with the pumped-out air which is pressure sensor is warped, and indications of a barometer will be distorted. It can lead to violation of tightness of the aneroid that the barometer completely will put out of action.
2. Turn a barometer a scale to yourself. In its center the trident of the mechanism, as a rule, is visible. At instrument readings of 750 mm Hg. all teeths of this conditional trident have to be parallel among themselves. In this case it is possible to say that the arrow is established correctly and did not get off concerning the barometer mechanism.
3. Attentively examine a barometer scale. All axes of mechanisms and also the thermometer if it is in a barometer that happens very often, have to be on one straight line. It will mean that the scale of a barometer was not turned concerning the case.
4. To solve the last two problems, remove glass of a barometer and turn a device scale that its indications coincided with a reference barometer. After that the aneroid will normally work. If the barometer owing to any reasons got off, adjust it the special screw by means of the screw-driver.
5. And here when the mechanism is warped, accurately sort a barometer, and install its mechanism in the correct situation with the help of correction of special levers which are in the mechanism, previously having weakened fastening of the aneroid. At the same time it is necessary to be very accurate not to damage the sensitive mechanism or integrity of the aneroid (a metal corrugated box with the pumped-out air). In this case the barometer can only be thrown out.