Pressure gauge is the most commonly used industrial process instrumentation. In use, such as the use of ambient temperature gauge reference working conditions beyond the limited temperature range, ambient temperature gauge because of the impact of temperature errors produced. The temperature gauge natural common error calculation. A wide variety of pressure gauge, pressure gauge of the temperature error calculation is relatively complicated. This tool can not only gauge the temperature error calculation, can be calculated by the temperature of various gauge indication after the basic error limit. Also provides a popular and intuitive dial gauge the relative error of temperature minimum number of sub-grid!

China's national standard stipulates that the use of ambient temperature gauge deviation from 20 ± 2 ℃ (0.25 Precision Pressure Gauge), 20 ± 3 ℃ (0.4 Precision Pressure Gauge) or 20 ± 5 ℃ (normal pressure gauge), the pressure gauge The indication error, (including zero)should not be greater than the limits prescribed by the following formula:

Δ = ±( δ + K Δ

Formula: Δ ── Ambient temperature gauge deviation from 20 ± 2 ℃ (0.25 Precision Pressure Gauge), 20 ± 3 ℃ (0.4 Precision Pressure Gauge) or 20 ± 5 ℃ (normal pressure gauge) when the pressure indication error limit,%.

δ ── China's national standard value stipulated in the basic error of the pressure that the absolute limit,% .0.25 Precision Pressure Gauge 0.25% 0.4 0.4% precision pressure gauge, pressure gauge 1.6 General 1.6% 2.5 General Pressure Gauge 2.5%, 4.0 General pressure gauge was 4.0%.

Δ

K ── Affected by ambient temperature gauge factor, 0.04% / ℃ (does not apply to constant elastic material, elastic material constant K value calculated in accordance with the provisions of the relevant material standard.)

Maximum value of a pressure gauge measuring 1MPa precision grade 0.4, dial grooves 200 points grid, the actual use of environmental temperature is 26 ℃.

Value δ = 0.4% t

Then Δ

Δ = ±( δ + K Δ

Then, the pressure gauge at 26 ℃ ambient temperature to allow use of the basic error of ±( 1MPa × 0.52% ) = ±0.0052MPa

For the visual purposes, we use the gauge at 26 ℃ ambient temperature allowed under the fundamental error ±0.0052MPa Converted into the equivalent of the size of the smallest sub-grid:

The pressure gauge the value of the minimum sub-grid scale value = pressure gauge dial gauge groove ÷ total number of grid points = 1MPa ÷ 200 = 0.005MPa / sub-grid

The pressure gauge at 26 ℃ ambient temperature to allow use of the basic error of ± 0.0052MPa equivalent to the size of the smallest sub-grid = ± (ambient temperature gauge allows the use of basic error ÷ gauge the value of the smallest sub-grid) = ± ( 0.0052MPa ÷ 0.005MPa / sub-grid) = ± 1.04 sub-grid. not only to use the pressure gauge at 26 ℃ ambient temperature allowed under the basic error of indication ± 1.04 个 smallest compartments.

- ① The upper limit of the pressure gauge measuring the drop-down list box, select 1MPa
- ② Accuracy class in the pressure gauge drop-down list box, select 0.4
- ③ Grid points in the pressure gauge dial the number of drop-down list box, select the 200 sub-grid
- ④ In the text box using the ambient temperature of 26
- ⑤ Reference temperature gauge conditions in the drop-down list box, select the 23 ℃. Later, the basic error in the indication limit the text box will show the temperature gauge in the reference work permit under the basic error of the results ± 0.004 MPa, in minimum value of sub-grid dial text box will show the minimum in the pressure gauge the value of sub-grid calculations 0.005 MPa, the fundamental error in allowing the equivalent of the text box will show a pressure gauge to deviate from the reference temperature conditions of the permit basic error is equivalent to gauge the size of the smallest sub-grid ± 1.04 个 smallest sub-cell, the fundamental error in allowing the text box showing the value of a gauge will appear to deviate from the reference temperature conditions, the basic error allowed, ± 0.0052 MPa .