Temperature shock test chambers GJB150, GB/T2423 and MIL-STD-8lOF have slightly different retention time regulations. In principle, the time required for the tested product to reach temperature stability at the test temperature. GJB150.5 specifies a lower limit of 1h, that is, if the temperature stabilization time is less than 1h, it must be 1h; if it is greater than 1h, use the time greater than 1h, GB/T2423.22 gives 5 time levels from 10min to 3h, The user uses the time closest to the measured product temperature stabilization time as the holding time; while the 810F method 503.4 does not specify the specific time or the optional time level, directly adopting the product to achieve temperature stability time or the product is in the environment. In the actual exposure time, in the temperature shock test chamber test, the most critical is to establish the stress caused by the inconsistent thermal expansion and contraction of different materials. The actual thermal shock is most likely to occur outside the product under test. The relevant information indicates that it is not necessary to achieve temperature stability throughout the product, as long as the external surface temperature of the test product is consistent with the test temperature. Although this opinion has some truths, it is also difficult to implement because it is impossible to install many sensors on the surface of the product. In addition, the heat transfer capacity of each part of the product is inconsistent, and the heat capacity of adjacent parts inside the test product is also inconsistent, so it is difficult to determine.
A hygrometer is an instrument used to measure the amount of water vapor in air, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other quantities such as temperature, pressure, mass, a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity. Modern electronic devices use temperature of condensation (called the dew point), or changes in electrical capacitance or resistance to measure humidity differences.
To be honest, with the number of gardening products we have today it is really hard to decide what to get. An indoor outdoor thermometer is very handy to measure the temperature inside your house or a greenhouse and outside in the garden. Wireless Hygrometer Thermometer is your best choice.
The best advantage of the outdoor/indoor thermometer is the ability to measure the temperature outside without you leaving the house. Also, its function is not only limited to the use in the garden and greenhouse.
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