Question 1: What is the accuracy level of the instrument? The higher the accuracy, the more sensitive, right? Why? The accuracy level of the instrument is actually the accuracy level, which is the grade of the instrument according to the accuracy, which determines the maximum allowable value of the basic error of the instrument. It is usually referred to as the accuracy class. The sensitivity of the instrument is the ratio of the output increment to the input increment after the instrument reaches steady state, the larger the ratio, the more sensitive, or the smaller the minimum input increment that causes the output change, the more sensitive. So high accuracy does not mean high sensitivity. Question 2: The type of accuracy level The accuracy level of instrumentation is generally divided into 0.1 grade, 0.25 grade, 0.5 grade, 1 grade, etc. A class of 0.1 means that the measurement error is less than or equal to 1/1000 of the maximum range. A scale of 0.25 means that the measurement error is less than or equal to 2.5 thousandths of the maximum range. A rating of 0.5 means that the measurement error is less than or equal to 5 thousandths of the maximum range. Level 1 refers to a measurement error of less than or equal to one hundredth of the maximum range. Question 3: How to choose the standard table when the calibration table of the instrument being calibrated is directly compared with the value of the standard instrument? First, the standard instrument is the same as the instrument being tested, if the meter is a DC voltmeter, the standard meter should also be a DC voltmeter; the second is to be compatible with the rated value of the instrument to be checked or not more than 25% of the rated value of the instrument to be tested; Third, the allowable error of the standard instrument should not exceed 1/3 of the allowable error of the instrument being tested. For example, if the scale is the same, the scale to be calibrated is 1.5, and the standard table should be 0.5. Question 4: Is it permissible for someone to constantly tap the case with their hands when they are calibrating the spring tube pressure gauge? This is not only permissible, but also mandatory, but the amount of hand change after tapping the case shall not exceed 1/2 of the absolute value of the maximum allowable error, the difference between the indication value before and after tapping and the standard value shall meet the accuracy requirements, and the difference between the reading of the same verification point after tapping on the upper stroke and the lower stroke shall not exceed the maximum allowable error value. Question 5: What should be paid attention to in the operation of steam flow transmitters and level transmitters with negative migration? For steam flow meters and level gauges with negative migration, it is not allowed to have positive and negative pressure valves and balance valves open at the same time during the operation of the three-valve group when starting or deactivating, even if they are open for a short time. When all three valves are open, the condensate in the condenser on the negative pressure side or the isolation liquid in the isolation tank will be lost, resulting in inaccurate instrument indication and even forced to stop operation. Question 6: Why do I need to compensate for the cold junction when measuring the temperature of thermocouples? The magnitude of the thermocouple thermoelectric potential is related to the temperature at both ends, and the temperature-thermoelectric potential relationship curve is indexed when the temperature of the cold junction is 0. In practical applications, since the cold junction of the thermocouple is exposed to space and is affected by the ambient temperature, the temperature of the cold junction in the measurement cannot be kept at 0, nor can it be fixed at a fixed temperature, and the thermoelectric potential is determined by both the hot and cold junction temperatures. Therefore, if the cold junction temperature changes freely, it will inevitably cause a measurement error, and in order to eliminate this error, the cold junction temperature must be compensated. If you have any questions about product consultation, product customization, agency, technical inquiry, quotation, etc., please contact Xingyi, 400-600-4496!