2-Point Temperature Calibration (Defined) - Honeywell Mini-AT User Manual

2) If only a single, line-pressure check is all that is to be attempted, proceed to step 4, then directly to
step 9.
3) Remove pressure from the selected pressure transducer.
4) Use a mag wand to scroll to the Live Pressure display (PCor or PLog) of the Meter Reader List.
5) Verify that the Mini-AT's live pressure reading displays 0.00 PSI +/- 0.25% of full scale.
6) If the pressure reading is within tolerance, proceed to step 9.
7) If the Mini-AT's displayed pressure reading is greater than 0.00, press the DOWN button on the
Mercor Mini Field Calibrator until it reads 0.00. If the Mini-AT's displayed pressure reads negative
(ex. -0.05), press the UP button until it reads 0.00.
8) Press the ENTER button to 'lock-in' the pressure reading. Note; The Mini-AT's LCD will go blank
for a second while the instrument is computing the new P-Zero value. When completed, the LCD
will return to a live pressure display and further adjustments are possible, if needed.
9) Apply line pressure to the Mini-AT's transducer. Compare the live pressure display to the pressure
reading on the calibrated pressure gauge. If the two readings are within tolerance, no further
adjustments are needed, proceed to step 11.
10) If the two readings are outside an acceptable tolerance, consider the most appropriate action listed
in item 6 of Single-Point Pressure Calibration (Defined) .
11) Use the mag wand to return the instrument to the Corrector Mode.
12) Unplug the Field Calibrator cable from the main board connection J2.
The above procedure compared the Mini-AT's live pressure to the pressure on a calibrated pressure gauge at
two different pressure points. An alternative would be to check the pressure at line pressure only. If the readings
are within tolerance, the pressure calibration could be assumed to be sufficient. However, any of the above
procedures should be subject to individual gas company policies.

2-Point Temperature Calibration (Defined)

A 2-Point temperature calibration requires that two different temperatures be applied to the instrument's
temperature probe and be sampled by the data acquisition circuits. A low temperature source, usually
an ice bath (32 degrees F) is used to determine the Temperature Zero Calibration. A higher temperature
source is used to determine the Temperature Span Calibration (gain). The default Calibration
Parameters require the Span Temperature exceed the Zero Temperature by at least 10% of the
instrument's temperature range.
The temperature probe provides a nonlinear, but very predictable temperature response for all rated
temperatures. The instrument's firmware contains the required information to produce a linear
temperature response for any connected temperature probe. The 2-point calibration process uses the
temperature offset and temperature span values to adjust for individual sensor variations. Once these
two points have been calculated and stored into memory, all other applied temperatures can be
determined by a linear interpolation.
Mini-AT User Guide
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