IET Labs, Inc. 1864-1644, User And Service Manual

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CONTENTS, FIGURES, AND TABLES
1864-1644 Positive Polarity Megohmmeter
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4.3.3 Measurement Time Constant ......................................................................... 15
4.3.4 Discharge Time .............................................................................................. 15
4.3.5 Large Capacitors, Very High Resistance ....................................................... 15
4.4 Resistance Measurements ........................................................................................ 16
4.5 Measurement of Voltage Coef fi cient ........................................................................ 16
4.6 Guarded 3-Terminal Measurements ......................................................................... 17
4.7 Remote Shielded Measurements .............................................................................. 17
4.8 Measurements Under Humid Conditions ................................................................. 17
Chapter 5: THEORY ....................................................................................19
5.1 General .................................................................................................................... 19
5.2 Circuit Description ................................................................................................... 19
5.2.1 General ........................................................................................................... 19
5.2.2 Type 1863 Megohmmeter (Figure 7.6) .......................................................... 19
5.2.3 Type 1864 Megohmmeter (Figure 7.9) .......................................................... 20
Chapter 6: SERVICE AND MAINTENANCE ..............................................21
6.1 Service ...................................................................................................................... 21
6.3 Cabinet Removal ...................................................................................................... 23
6.4 Troubleshooting ....................................................................................................... 23
6.4.1 General ........................................................................................................... 23
6.4.2 Test Voltages .................................................................................................. 24
6.5 Calibration Procedure .............................................................................................. 24
6.5.1 General ........................................................................................................... 24
6.5.2 Meter Tracking ............................................................................................... 24
6.5.3 Voltage Accuracy .................................................................................................. 24
6.5.4 Range-Resistor Accuracy ............................................................................... 25
6.5.5 Coarse ∞ Adjustment ..................................................................................... 25
6.6 Knob Removal ......................................................................................................... 26
6.7 Knob Installation ...................................................................................................... 27
6.8 Meter Cover Care ..................................................................................................... 27
Chapter 7: PARTS LISTS AND DIAGRAMS ..............................................29