EN 837-1-1998 pdf download.Pressure gauges Pait 1: Bourdon tube pressure gauges Dimensions, metrology, requirements and testing.
10.3 Temperature effect
The gauge to be tested will be subjected to the tilaXifliUfli and nilninnim ambient temperature from 9.5.1 in steps of 20 °C from reference temperature to the maximum and minimum ambient temperature. After having attained themial equilibrium the tests described ir 10.2 are carried out.
10.4 Endurance
The tests for the requirements given in 9.4 are as follows.
10.4.1 Gauges suitable for maximum steady working pressure 75 % of the maximum scale ealue
10.4.1.1 Steady p?rSSure
The gauge shall be pressurized up to the maximum scale value and the pressure maintained for 12 h.
10.4.1.2 Ckr-pirssu ir
The gauge shall be pressurized according to the requirements of 9.4.1.2 and maintained for 15 mm.
10.4.1.3 Cyclic pir.ssu i
The gauge shall be subjected to a pressure fluctuating approximately sinusoidally between (30±5) % and (60±5) % of the maximum scale value at a frequency of between 20 and 60 cycles per minute for the number of cycles stated in 9.4.1.3.
If the available equipment will not operate at the minimum frequency of 20 cycles per minute when testing gauges above 1000 bar the frequency may be reduced to 1 cycle per minute itumumnum.
10.4.2 Gauges suitable for maxim urn steady working pressure equal to the maximum scale talue
10.4.2.1 Steady pressure and overpirssure The gauge shall be pressurized up to 1,3 times the maximum scale value and the iressure niamtained for 12 h.
10.4.2.2 Cyclic pressure
The gauge shall be subject to a pressure fluctuating
approximately sinusoidally between (30±5) % and
(95±5) % of the maximum scale value at a frequency of between 20 and 60 cycles per minute for the number of cycles slated in 9.4.2.2.
If the available equipment will not olx’rate at the minimum frequency of 20 cycles per minute when testing gauges above 1 0(X) bar the frequency may be reduced to 1 cycle per minute minimum.
10.4.3 Accuracy after endurance test
After completion of the endurance testing the gauge should be left undisturbed for 1 h. Then the error when tested in accordance with 102 shall not exceed 1,2 times class.
For rangesObarto l000barand0bar to l600bar the error shall not exceed 1,5 times class.
10.5 Rated temperatures in service
The pressure element assembly is to be placed in a climatic eha.niber for 24 ii at. the upper temperature extreme at a pressure of 2,5 times the maximum scale value with a maximum scale value LIP to 1 000 bar, and 1,5 times the maximum scale value with a maxim run scale value above 1 000 bar, reS)eC1ively. Afterwards, the leak test is carried out at ambient room tenhl)erature as 10.10. After this test measuring performance is not required.
10.6 Rated storage temperatures
The complete, unpressurized gauge is to be placed in a clmmtic chamber for a minimum of 24 h at each temperature extreme.
Inspect immediately for any changes in appearance U1(l, after 1 ii at reference temperature, test for accuracy and hysteresis, and leakage to 10.2 and 10.10.
After the test the gauge shall satisfy the re(luirements given in 9.1, 9.2 and 9.5.2 for accuracy and hysteresis, and no change of appearance shall occur.
10.7 Protection against ingress of water and foreign particles (degree of protection) As sl)ecifw(l in EN 60529.
10.8 Effect of mechanical shock
Shock test equil)rneflt as given in EN 60068-2-27. Tests with 150 mIs2 half sinewave in the two directions of three rectangular axes. Perform three shock loads in each plane, this being 18 shocks altogether. The gauge shall be pressurized with 50 % of the maximum scale value and be niotuited in its normal manner. After the test the gauge shall satisfy the requirements for test the gauge shall satisfy the requirements for accuracy and hysteresis as given in 9.1 and 9.2.
10.9 Effect of mechanical vibration The gauge shall be mrnufled on a vibration test equipment as given in EN 60068-2-6 in its normal maimer and tested at conditions as described in 9.5.5. It shall be pressUrlze(l to 50 % of the maximum scale value. After the test the en-or shall not exceed 1,5 times class.
10.10 Leak test
The leak test shall be conducted at the maximum scale n?a(ling. Gauges with a maxinnmi scale rea(liIlg UI) to 25 bar shall be tested on gas. Above this the test may be conducted with liquid.
10.11 Mounting position
The gauge shall be mounted inclined forwards at 5° to its normal position and tested for accuracy and hysteresis iii accordance with 10.2. The change iii in(lieatmon shall not exceed 0,5 times class. It shall then be tested similarly inclined backwards, to the right. an(l to the left.EN 837-1-1998 pdf download.