EMA 84 Instruction Manual
9
4
Zero-point calibration
The instrument has a built-in potentiometer for calibrating the zero-point, a procedure
that must be carried out with the
pressure ports and/or valves open
before every
measurement. This is accomplished by turning potentiometer dial B until the display
reads 000. Zero-point calibration allows the instrument to compensate for positional
errors, temperature-induced errors and long-term instrument drift. The zero point
must be calibrated with the instrument in the same position as it will be in when
operated.
The potentiometer may not be used to compensate for errors caused by overloading
the pressure measurement capsule; in other words, the zero-point can no longer be
calibrated in this case and the instrument must be returned to the manufacturer.
5
Troubleshooting
Error description
Potential cause
Corrective action
display does not appear
dead battery
install new battery
use a 9V IEC 6 LR 51 battery
instrument returns false
values
zero point has shifted
battery is low
adjust zero point
(see section 4)
display reads ‘LOW BAT,’ i.e.,
replace the battery
zero-point calibration
cannot be performed
defective pressure measurement
capsule
send the instrument to the
manufacturer for repair
