As everyone knows about pressure gauges, it uses elastic elements as sensitive elements to measure and indicate pressure above ambient pressure. The application of pressure gauges is extremely common, it covers almost all industrial processes and scientific research fields. Pressure gauge applications can be found everywhere in heat pipe networks, oil and gas transmission, water and gas supply systems, and vehicle repair and maintenance plants.

       Today, I would like to introduce to you the testing steps of several pressure gauges:

       First, visual inspection

       1. The surface of the newly-made pressure gauge should be smooth and even, without rust, burrs, and no electroplating defects, and the welding place should be smooth and beautiful.

       2. The reading part, the glass cover or plastic cover of the pressure gauge should be colorless and transparent, and there should be no defects that hinder the reading. The indexing plate should be flat and clean, and the marks should be clear and legible.

       3. For pressure gauges with limited stop nails, when there is no pressure, the pointer should be close to the stop pin. For pressure gauges with unlimited stop nails, when there is no pressure, the pointer should be within the 0-bit mark.

       4. If the pressure gauge is filled with liquid, the liquid should be clear and transparent, free of impurities or floating objects, and its liquid level should be 0.25D-0.3D (D is the outer diameter of the instrument) above the watch case and no Leakage phenomenon.

       Second, the meter

       1. Select a suitable standard, the allowable error value of the standard should not be greater than 1/4 of the allowable error value of the pressure gauge under test.

       2. Standard appliances can use spring tube type precision pressure gauge and vacuum gauge, piston pressure gauge, piston vacuum pressure gauge

       Third, verification of indication error, return error, and tap displacement

       1. The verification method of indication error, the indication verification of the pressure gauge is carried out according to the index line marked with numbers, and the pressure is gradually increased (or depressurized) gradually at the verification time. When the indication reaches the upper detection limit, the pressure source is cut off. Withstand the voltage of 3MIN, and then return to the test in the reverse order of the original test point in a steady step-down (or step-up).

       2. For the return error, for the same point check timing, during the step-up (or step-down) and step-down (or step-up) check, the specified allowable error value.

       3. Tap the displacement. For each point of checking, during the step-up (or step-down) and step-down (or step-up) check, the indication value caused by tapping the case is not greater than the specified allowable error 1/2.

       4. Indication error, for each verification point, during the step-up (or step-down) and step-down (or step-up) check, the difference between the value displayed on the front and back of the case and the value displayed on the standard device should meet the requirements .