FMC Corporation - Talstar 80 Manual De Usuario

Commissioning

Proline Promass 80 PROFIBUS PA

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All measuring devices are calibrated with state-of-the-art technology. The zero point obtained in 
this way is printed on the nameplate. 
Calibration takes place under reference operating conditions. 

Consequently, the zero point adjustment is generally not necessary!

Experience shows that the zero point adjustment is advisable only in special cases:
• To achieve highest measuring accuracy also with very small flow rates.
• Under extreme process or operating conditions (e.g. very high process temperatures or very high 

viscosity fluids).

Note the following before you perform a zero point adjustment:
• A zero point adjustment can be performed only with fluids that have no gas or solid contents.
• Zero point adjustment is performed with the measuring tubes completely filled and at zero flow 

(v = 0 m/s). This can be achieved, for example, with shutoff valves upstream and/or downstream 
of the sensor or by using existing valves and gates.
– Normal operation 

→ valves 1 and 2 open

– Zero point adjustment with pump pressure 

→ Valve 1 open / valve 2 closed

– Zero point adjustment without pump pressure 

→ Valve 1 closed / valve 2 open

a0003601

Fig. 35: 

Zero point adjustment and shutoff valves

"

Caution! 
• If the fluid is very difficult to measure (e.g. containing entrained solids or gas) it may prove 

impossible to obtain a stable zero point despite repeated zero point adjustments. In instances of 
this nature, please contact your E+H service center.

• You can view the currently valid zero point value using the ZERO POINT function (see the 

"Description of Device Functions" manual).

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