Fluke 80T-150UA - Manual (Page 5)

Battery Replacement
XW Warning
To avoid electrical shock, remove the probe from the
measurement surface before opening the case. Totally
reassemble the instrument before attempting to use it.
1. Set the power switch to the OFF position.
2. Disconnect the 80T-150UA from the DMM.
3. Turn the 80T-150UA so the power switch is facing down. Remove
the single screw located between the banana plugs.
4. Grasp 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 80T-150UA as follows. Mate the two case halves at
the end where the cable enters the case, then "hinge" the two
halves together. Replace the case screw, being careful not to pinch
the probe cable or battery wires.
Performance Test
Complete the calibration procedure without opening the temperature-to-
voltage converter assembly and without making any calibration
adjustments. Observe the readings given in [brackets]. Other readings
are for calibration only.
Calibration
The calibration cycle of one year is recommended to maintain the unit
within the specifications given earlier. The equipment required for
calibration is listed in the table following the calibration procedure.
Note
Values given in brackets apply to the Performance Test.
Perform the following steps to calibrate the 80T-150UA:
1. Access the interior of the temperature-to-voltage converter by
removing the bottom case screw and separating the case halves.
2. Connect the 80T-150UA to a DVM with 10
μ
V resolution, and select
mV dc range.
3. Select the
°
C position of the switch. Immerse the probe tip 5.1 cm (2
inches) into a mercury thermometer monitored 0
°
C bath, and allow
a full 5 minutes for the reading to stabilize.
4. Adjust VR3 and VR1 (see Figure 2) to obtain the following reading:
0.00
± 0.05 mV dc [0 ± 0.2 mV dc]
5. Select the ° F position of the switch, and adjust VR2 to obtain the
following reading:
32.0
± 0.1 mV dc [32.0 ± 0.4 mV dc]
6. Select the
°
C position, and move the probe tip to a 70
°
C bath and
again allow the reading to stabilize.
7. Adjust VR4 to obtain a DVM reading that agrees with the bath
temperature (BT) as monitored by a mercury thermometer.
°
C BT
±
0.05 mV dc [BT
±
0.2 mV dc]
8. Select the
°
F position, and verify that the output is within
±
4 mV dc
of the bath thermometer reading. If necessary, change the DVM
range to obtain an on-scale reading.
9. Return the probe tip to the 0 ° C bath wait 10 minutes, then check the
output. If readjustment is necessary, repeat steps 4 through 8 until
the readings can be obtained without adjustment.
10. Set the 80T-150UA switch to the OFF position, and remove the 80T-
150UA from the DVM.
11. Reassemble the 80T-150UA.
12. The 80T-150UA is now calibrated.
Cleaning
Clean the test tool with a damp cloth and a mild soap. Do not use
abrasives, solvents, or alcohol. These may damage the text on the test
tool.