7
- Atmospheric pressure ranges from 84.0 to 106.7 kPa.
The degree of protection of the flow meter corresponds to the IP67
or IP68. The required degree of protection of the device is determined
when ordering.
1.2.6. The power supply of the flow meter is provided from an internal lithium C
size battery with a nominal voltage of 3.6 V.
1.2.7. Appearance, overall dimensions and weight are given in Appendix A.
1.3. Metrological characteristics
1.3.1. The limits of permissible error in measuring the average volumetric flow
rate, the volume of liquid in any direction of flow do not exceed the values
given in table 2.
Table 2
Error formula
Relative error limit value
v
0.1
0.95
δ
1.0 % at v > 2.00 m/s
1.5 % at v > 0.19 m/s
2.0 % at v > 0.10 m/s
3.0 % at v > 0.05 m/s
4.0 % at v > 0.033 m/s
where v
– flow velocity, m/s.
1.3.2. The diagram of real measurement error of the flow meter is shown in
Fig.1.
+4%
+2%
-4%
-2%
v,m/s
0.033
5
+1%
-1%
0.01
2
Fig.1. Diagram of real measurement error of the flow meter
