Fluke 27 Service Manual

27
Service Manual
3-16
3-20. DC Voltage Connection
The dc voltage function must be calibrated before calibrating the other functions. Use the
following procedure to calibrate the dc voltage function.
1. Connect the DMM Calibrator to the UUT volts/ohms/diode-test input terminal and
common. Refer to Figure 3-4 for calibration component locations.
2. Select the dc voltage function (F) on the UUT.
3. Switch on power to the DMM Calibrator, and program the Calibrator output for
2.700 V dc.
4. Adjust potentiometer R19 on the UUT for a display indication of 2.700 V on the 3 V
range.
5. Program the DMM Calibrator for zero output, and disconnect the Calibrator from the
UUT.
C4 (320 V AC Range)
C10 (1000 V AC Range)
C6 (3.2 V AC Range at 10 kHz)
C8
(32 V AC Range)
R7
(3.2 V AC Range)
R19
(DC Volts)
aac06f.eps
Figure 3-3. Calibration Adjustment Locations
3-21. AC Voltage Calibration
There is a single ac-to-dc converter adjustment for basic ac voltage accuracy. However,
each ac voltage range must be calibrated independently for high frequency accuracy.
Variable capacitors provide these high frequency adjustments. There should be no
interaction between the various ranges when adjustments are made in the specified order.
Use the following procedure to calibrate the ac voltage ranges.

Fluke 27 Specifications

General

Display Type	LCD
AC Voltage Range	0.1 mV to 1000 V
DC Voltage Range	0.1 mV to 1000 V
AC Current Range	0.1 μA to 10 A
DC Current Range	0.1 μA to 10 A
Battery Type	9V
Continuity	Yes
Diode Test	Yes
Safety Rating	CAT III 600V
AC Current Accuracy	±(1.5% + 2 digits)
Resistance Accuracy	±(0.2% + 1 digit)
DC Voltage Accuracy	±(0.1% + 1 digit)