MRU-120HD –USER MANUAL
CONTENTS
1Safety ................................................................................................................5
2Menu..................................................................................................................6
2.1 Measurement settings.............................................................................................. 6
2.1.1 Mains frequency................................................................................................................7
2.1.2 Calibration of the measurement clamp C-3 .......................................................................7
2.1.3 Earth resistivity settings.....................................................................................................9
2.2 Meter settings...........................................................................................................9
2.2.1 LCD contrast...................................................................................................................10
2.2.2 AUTO-OFF settings ........................................................................................................10
2.2.3 Display settings...............................................................................................................10
2.2.4 Date and time..................................................................................................................10
2.2.5 Battery discharging .........................................................................................................11
2.2.6 Program update ..............................................................................................................11
2.3 Language choice.................................................................................................... 11
2.4 Information on the manufacturer............................................................................ 11
3Measurements................................................................................................12
3.1 Measurement of resistance of earth connection and equipotential bonding (2P)......... 12
3.2 Calibration of the test leads.................................................................................... 14
3.2.1 Auto-zeroing on...............................................................................................................14
3.2.2 Auto-zeroing off...............................................................................................................15
3.3 Earth resistance measurement with 3-pole method (RE3P) ................................... 16
3.4 Earth resistance measurement with 4-wire method (RE4P).................................... 19
3.5 Earth resistance measurement with 3-pole method with additional clamp (RE3P+C)... 22
3.6 Earth resistance measurement with two-clamp method (2C)................................. 25
3.7 Earth resistivity measurement (ρ)........................................................................... 27
4Memory ...........................................................................................................30
4.1 Saving of the measurement results in the memory................................................ 30
4.2 Memory erasing ..................................................................................................... 31
4.3 Memory browsing................................................................................................... 32
5Data transmission..........................................................................................33
5.1 Computer connection accessories......................................................................... 33
5.2 Connection of the meter to a computer.................................................................. 33
6Power supply..................................................................................................34
6.1 Monitoring of the power supply voltage.................................................................. 34
6.2 Fuse replacement .................................................................................................. 34
6.3 Charging of rechargeable batteries........................................................................ 35
6.4 Discharging of rechargeable batteries.................................................................... 36
6.5 General principles regarding using Ni-MH rechargeable batteries......................... 37
7Cleaning and maintenance ...........................................................................38
8Storage............................................................................................................38
9Dismantling and disposal .............................................................................38
10 Technical data................................................................................................39
