Fluke service manual with calibration procedure.
Fluke recommends 5700A calibrator, but we will use poor-man DC standard, EDC MV106.
Initial inspection, "before calibration" state.
On right side - ADC calibration fixture (two-copper terminal jack made from two thermocouple T jacks).
Cal sticker is tampered.
-82°C with tested K-type thermocouple hanging in +25C room temp ain't right.
Closeup for connector used for voltage source (EDC MV106 DC standard calibrated to Keithley 2001 with Tek cal 5.FEB.2014) connection to Fluke 52-2 inputs.
I used copper wire from UTP LAN cable.
0.0000v set - meter shows 20-30C...
Calibration A-D convertor by providing 80.0000mV and -8.00000mV to inputs.
-8.00000mV read as -7996.9 uV, which is in range for calibration requirements of –7995.0 to –8005.0.
Calibration reference point:
REF point offset is 3.8C.
After corrected offset:
"After calibration" Performance test values (K-Type Thermocouple) with icebath.
Channel 1 on left, channel 2 on right:
1. 0.0000 mVDC / 0.0 °C
2. 0.9193 mVDC / 23.0 °C
3. -5.7297 mVDC / -190.0 °C
4. 40.8853 mVDC / 990.0 °C
5. 48.8382 mVDC / 1200 °C
Same K-type probe reads correct +25.6°C now.
Thanks for watching
P.S.
Used gear:
Calibrated Keithley 2001 Multimeter (5.FEB.2014)
Keithley 2002 Multimeter (10.APR.2007)
Calibrated EDC MV106 DC Voltage standard +-30ppm/°C (8.FEB.2014)
Calibrated Keithley 2400 Sourcemeter (14.JAN.2014)