Hi guys,

Can some one tell me what does the static zero in a transmitter mean??

 

A zero effect error applies across the entire span of the instrument as an offset or bias value, so instruments used in applications where a zero shift can be significant are more closely examined for the effects of temperature and pressure on the device's zero.

There is general consensus regarding the difference between a ‘zero check’ and ‘static zero check’ on a DP flow transmitter, where a zero check checks the transmitter output at 4.00 mA when its high side and low side chambers are equalized at the atmospheric pressure, but a static zero check checks the transmitter output at 4.00 mA when its high side and low side chambers are equalized at the operating pressure.

The "Best Practice Guide: Impulse Lines for Differential-Pressure Flowmeters", TUV NEL Ltd., 2005; page 12 states, "It is usually desirable to be able to join the high and low pressure sides of the differential-pressure transducer so that the signal from the transducer can be obtained with no differential pressure but at line pressure; this is often called performing a high-static zero check."

Some industrial pressure transmitters provide specific values for calculating the effects of temperature and/or pressure on the transmitter's zero, where the temperature effect is per X°C and the pressure effect is per Y psig of static line pressure. The spec sheet I'm looking at calls the factor, "Zero Static Pressure Effect per 1,000 psi (70 bar)"