WIKA 73 - Manual (Page 10)

GB
11591367.02 05/2012 GB/D/F/E
10 WIKA operating instructions models 73, 74 (ATEX)
3. Specifications
Specifications Model 73 Model 74
Measuring element Gas-pressure inert gas filling
Nominal size 100, 160, 144 x 144 100
Instrument version
■ Model A7x
■ Model R7x
Back mount (axial)
Lower mount (radial)
■ Model S73
■ Model F73
Back mount, adjustable
stem and dial
Instruments with capillaries
Permissible ambient
temperature
0 ... 40 °C
Working pressure
■ Continuous load (1 year)
■ short term (max. 24 h)
Measuring range (EN 13190)
Scale range (EN 13190)
Case, ring Stainless steel 1.4301
Stem, process connection Stainless steel 1.4571 Stainless steel 1.4435
Ingress protection
per EN 60529/ IEC 529
IP 65
IP 66 (liquid-filled)
IP 65
(option: IP 66)
For further specifications see WIKA data sheets TM 73.01 or
TM 74.01 and order documentation.
4. Design and function
4.1 Description
The gas actuated thermometer consists of a stem, capillary and
Bourdon tube in the casing. These parts are combined to form a
single unit. The entire measuring system is filled with an inert gas
under pressure.
A change in temperature will cause a change in internal pressure
in the stem. The pressure deforms the measuring spring and the
deflection is transferred to the pointer via a dial movement.
3. Specifications / 4. Design and function