Pressure Gauge WIKA Model 711.12 is based on two independently operating Bourdon tube measuring system. The instrument is therefore able to show the pressure from two measuring points and the resulting differential pressure on one display.
Differential pressure display
The standard version is designed with two pointers and a gauge pressure scale. The pointer for the minus connection is connected to an additional moving dial. On the scale of the moving dial, the differential pressure (± 50 % of the main scale’s full scale value) can be read directly.
Alternatively, in the version without additional moving dial, the differential pressure is not indicated
In the version with a subtracting movement, the differential pressure is indicated with only one pointer (the individual pressures of plus and minus connection are not displayed). The variance of scale versions ensures an optimal readability of all operating parameters.
The models 731.12 and 733.02, with wetted parts from stainless steel, have been specifically designed for the requirements in the process industry.
For harsh operating conditions, the instruments are also available with an optional liquid filling.
APPLICATIONS
- Heating, ventilation and air-conditioning
- For gaseous and liquid media that are not highly viscous
- Models 731.12 and 733.02 also for aggressive media
- Models 713.12 and 733.02 with liquid-filled case are suitable for high dynamic pressure loads and vibrations
SPECIAL FEATURES
- Scale ranges from 0…0.6 bar to 0…1,000 bar
- Two process connections and two independent pointers
- Differential pressure display with moving dial
- Cost-effective and reliable
STANDARD VERSION
Version
Two independent measuring systems, process connections in line
Nominal size in mm
100, 160
Accuracy class
1.6
Scale ranges
0 … 0.6 to 0 … 1,000 bar
Scale range must be selected in relation to the maximum total pressure applied!
In heating systems with circulating pumps, the total pressure applied is usually defined
as equal to the hydrostatic pressure plus the pump pressure.
In order to ensure a good readability, the differential pressure should not drop below
1/6 of the full scale value.
Pressure limitation
Steady: Full scale value
Fluctuating: 0.9 x full scale value
Short time: 1.3 x full scale value
Permissible temperature
Ambient: -20 … +60 °C
Medium: Model 711.12:
+60 °C maximum (soft soldered)
+100 °C maximum (brazed)
Model 731.12: +200 °C maximum
Temperature effect
When the temperature of the measuring system deviates from the reference
temperature (+20 °C): max. ±0.4 %/10 K of full scale value
Pressure elements
Model 711.12:
< 100 bar: Copper alloy, C-type, soft soldered
≥ 100 bar: Stainless steel, helical type, brazed
Model 731.12:
Stainless steel, all pressure ranges, welded
