10
Calibration of Digital Gauge
Gauge accuracy can be checked visually whenever it is switched on. If the unit is
used more than 15,000 times, a calibration reminder message (CAL) will appear on
the digital display. Any digital gauge that displays this message should be returned
for re-calibration to ADC’s Service Department. Only ADC or an authorized service
technician is qualified to perform this calibration service.
Do not attempt to recalibrate the gauge yourself.
In addition to the visual inspection indicated above, we also recommend you
perform the following calibration check on an annual basis:
• Connect your gauge to a high-quality, known pressure standard using ADC’s “Y”
Test Kit (part number 991)
• Pressurize the gauge to 299 mmHg
• Reduce the pressure at a rate no greater than 10 mmHg per second, and stop to
check at the following test points: 299mmHg, 250 mmHg, 150 mmHg, 100 mmHg,
and 50 mmHg. Your gauge should be /-3 mmHg of your reference stan-
dard.
ADC recommends using the most sensitive pressure standard possible when per-
forming this calibration check, as your ability to measure the accuracy of a gauge
depends on the sensitivity of the pressure standard. If you are using a reference
pressure standard that is only calibrated to +/- 3 mmHg (such as a mercury col-
umn or aneroid gauge), then you will only be able to determine the accuracy of the
test gauge to /- 6 mmHg. If you use a reference pressure standard that is
+/- .01 mmHg (such as a digital pressure standard), you will be able to determine
the accuracy of the gauge being tested to /- 3.01 mmHg.
In the event that the gauge is ever in need of calibration, simply return to ADC.
Damaged or broken parts will be replaced as needed at a minimum charge. Refer to
the warranty for specific details of warranty coverage.
