How are the thermal resistors and thermocouples in your factory tested? Is it necessary to send them to a calibration laboratory for testing?
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How are the thermal resistors and thermocouples in your factory tested? Is it necessary to send them to a calibration laboratory for testing? Is it necessary to attach a mark indicating successful inspection, and what is the inspection interval?
Classified as Category C; after passing the factory inspection, it is used until it breaks down, without any further inspections or installation of a certificate of conformity.
Based on the classification, Grade A requires mandatory inspection, Grade B requires periodic calibration, usually carried out during the equipment’s maintenance period, and Grade C requires a one-time calibration. Class B and C calibration laboratories conduct self-calibration, while Class A laboratories send their equipment to external metrology institutes for calibration. It is necessary to paste the calibration label.
Our factory has used many of these devices without conducting any inspections. Generally, for testing secondary instruments, one can buy a DC resistance tester (to be used for testing) or a signal generator. If it’s necessary to check whether platinum resistance thermometers are accurate, then a temperature calibration oven should be purchased (to be used for testing)
For resistors, pull them out to measure their resistance; for thermocouples, measure their MV value. They are classified as Category C, and no further testing is required. The transmitter unit will perform inspections; generally, such locations fall into Category B, requiring calibration once a year using a resistance box. Attach the certificate to the transmitter housing
Thermal resistors and thermocouples are consumable parts, and random inspections can be carried out before they are stored. If you conduct the testing yourself, you need the corresponding equipment, which involves a significant investment. And it must have **authorization from the measurement management department**. It is generally possible to require the supplier to provide calibration records in the purchase contract.
Our company conducts its own testing, or we can also use third-party testing!
No need; we have our own testing equipment, and it’s necessary to compare results with those from the metrology institute on an annual basis, usually once a year
Our unit has not been tested since it was put into use; is it not necessary to test it, just use it until it breaks?
Internal comparison is possible, as well as third-party testing! JJG160-2007，JJG229-2010.