Crystal MultiCal KPA/PSI - Manual (Page 3)

PN: 1763 Rev C, 4/2004
Page 3 of 8
C R Y S T A L
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5. “Zero” the MultiCal. Without any pressure or vacuum applied to the module turn the
knob opposite the banana plugs until your meter reads precisely zero. Prior to taking
measurements, and recommended when changing scales, the module should be
“zeroed” at barometric pressure.
Most multimeters “forget” the “relative” setting when changing from mV to any other
scale, even just to Volts. Some meters autorange from mV to Volts and then lose the
“relative” value. In these cases the zero knob may be more convenient than the “relative”
button on the multi-meter.
The zero reading may also shift when the MultiCal is shifted from a vertical to a
horizontal orientation. This is due to the oil filling that transmits the pressure signal
from the stainless steel diaphragm to the silicon pressure sensor. The magnitude of the
shift is typically 0.07 kPa or less.
6. Apply pressure to the MultiCal. If the meter reads overrange, change the multimeter
range to DC volts (instead of mV). Note: The decimal place will be for volts. Multiply the
reading by 1000. For example, 0.200 V would be 200 kPa.
Battery Replacement
1. Set the power switch to the OFF position.
2. Disconnect the MultiCal from the multimeter and any pressure connections.
3. Turn the MultiCal so the power switch is facing down. Remove the single screw located
between the banana plugs.
4. Grasp the one case half in each hand. Pull the two halves apart, beginning at the end
with the banana plugs.
5. Remove and replace the battery.
6. Reassemble the MultiCal. To reassemble, mate the two case halves at the end opposite
the banana plugs, then “snap” the two halves together.