Manual

CDG045-OP-LIT (2010-1) 25
4.2.2 <ZERO> Adjustment with Ramp Function
The ramp function allows to adjust the zero at a known reference
pressure within the measurement range of the gauge.
It also permits to adjust an offset of the characteristic curve in
order to
• compensate for the offset of the measuring system or
• obtain a slightly positive zero for a 0 … 10 V AD converter.
The offset should not exceed 2% of the F.S. (+200 mV). At a
higher positive offset, the upper limit of the measurement range
is exceeded.
Zero adjustment using the ramp function can be
performed via
• the <ZERO> button on the gauge,
• the RS232C interface (→  [1]).
Recommended procedure for adjusting the offset of a
measuring system: → Notice  22.
 Operate the gauge for at least 1 hour (until the signal is
stable).
 Push the <ZERO> button with a pin (max. ø1.1 mm) and
keep it depressed. The <STATUS> LED starts blinking.
After 5 s, the zero adjustment value, starting at the current
output value, keeps continually changing (ramp) until the
button is released or until the setting limit (max. 25% F.S.)
is reached. The corresponding output signal is delayed by
about 1 s.