Comark C9551 - Manual (Page 12)

11
4 . OTHER FUNCTIONS
4.1 Battery Low
Low battery is indicated by the symbol BAT on the
display. Replace the battery as soon as possible after
this symbol appears.
4.2 Over Range Pressure
If the pressure measured (either positive or negative
pressure) exceeds the full scale of the instrument, the
display will show – – – –
If this occurs the pressure must be reduced to avoid
damage to the sensor in the instrument.
4.3 Over 9999 Reading Indication
If the numeric value for display exceeds ±9999, with
or without a decimal point, the display will blink and
suppress the top (5th) digit, whilst continuing with
correct values of the lower 4 digits.
4.4 Differential or Gauge Measurement
C9500 series instruments can be used in either a gauge
or differential pressure measurement system.
Gauge:
For positive gauge measurements the negative
(-ve) port should be left open to atmospheric pressure
and the positive (+ve) port used to input the pressure.
For negative gauge measurements the positive (+ve)
port should be left open and the ‘vacuum’ applied to
the negative (-ve) port. Please note that in this case
the reading displayed will be positive even though a
vacuum is being measured.
Differential:
When measuring differential pressures, ensure that the
most positive (+ve) pressure is applied to the positive
(+ve) port.