Pressure type thermometer inspection procedures

Pressure type thermometer inspection procedures are mainly the following steps: 1, the accuracy of inspection: ( In second class standard thermometer for standard, constant temperature trough as testing equipment, see figure 1) Check point should be evenly distributed in each measurement range, the permissible error of & plusmn; 2. 5%. The tapping displacement change quantity shall be no greater than the permissible error absolute value of 50%. Pointer process should be smooth, no jump needle, needle card phenomenon. 2, visual inspection: ( Visual) Visible parts have no obvious blemishes, scratch or damage; Sheet glass should maintain a transparent light, without oil. 3, table card test: ( Visual) Color scale, trademarks and conform to the requirements of the work order; Requirement for printing quality, information on the card printing content complete and clear. 4, structure inspection: ( Visual inspection and use vernier caliper and thread ring gauge) Installation, the size of the thermal components, pointer, pan, cover, connector, connecting pipe material and size should be accord with the requirement of work order and accessories. Pointer must not have paint tumor, burr; Joint thread must not have crack, collapse, ground bald and sliding tooth phenomenon; Connecting pipe should be orderly winding and strapping; The end of the temperature sensing element without welding pits; The attachment parts intact. 5, sampling scheme adopted GB/T 2828 standard, IL: S - 4,AQL: 1。