What are the steps of the hygrometer calibration?
Hygrometer is a device that measures relative humidity in the air. Its most common use is in a closed container that needs to be maintained at specific humidity, such as humor of a cigar. An analog hygrometer usually uses a needle with a numbered scale to ensure relative humidity, while the digital display provides a specific humidity number. The steps in the calibration of the hygrometer generally include exposure to the atmosphere hygrometer with known humidity and the hygrometer treatment to display this moisture value. Calibration is usually only necessary for analog hygrometers.
The hygrometer calibration requires a certain specific equipment in addition to the hygrometer itself. This includes a soda plastic bottle cap and a airtight plastic food container large enough to hold the hygrometer. Other materials needed to calibrate the hygrometer include a small amount of table salt, water and a flat head screwdriver that suits the calibration for the hygrometer.
The first step is to pour teaFor a teaspoon of salt into a clean cap of a bottle on dry soda bottles. Only enough water should be added so that salt can be without actually dissolve salt. The bottle cap and the hygrometer should then be placed in the plastic container as close as possible. The lid on the container should be sealed without pressing down to ensure that the air in the container is at normal pressure.
The container can be open after about eight hours and the hygrometer removed. After reading the humidity level, the hygrometer can be modified if the reading does not show 75 percent. This procedure for the hygrometer calibration is based on the fact that moist salt generates a relative humidity of 75 percent when the test is properly performed.
The hydrometer is set by turning the calibration screw. This generally involves the Calibration turning in clockwise and increases the hygrometer reading and counterclockwise to reduce the hygrometer value. PTerry Hygrometer does not have a calibration screw, any deviation from 75 percent should be recorded and used for future measurements. For example, if the hygrometer reads 65 percent after the test, ten percent should be added to measure the hygrometer moisture.
Analog hygrometers should be calibrated for approximately every six months because they tend to fall out of adjustment over time. Digital hygrometers are usually calibrated in the factory and users are not adjustable. A faster but less accurate method of hygrometer calibration involves packing the entire hygrometer with a damp cloth and setting the hygrometer so that 96 percent can be read.