PRECISION PORTABLE MICRO OHMMETER

5897 Portable Precision Micro-ohmmeter 100 A
An accurate mains/battery powered portable 100A  Micro Ohmmeter. Using the 4 terminal 
measurement technique the 5897 gives basic accuracy of 0.2% and an overall resistance
range of 0.1 µΩ to 40 Ω. With an internal mains re-chargeable battery supply the 5897 Micro Ohmmeter may be used “in the field” for periods of up to 8 hours without requiring recharging. 
A standard RS232 computer interface is included that may be used for printing resistance values or 
downloading measurements that have been stored in the instrument’s memory. 

Precision Micro-ohmmeter

The 5897 Micro Ohmmeter can be used fully auto-ranging or with manual range selection if
required.
Each of the 6 ranges has a choice of high or low measuring current. 
Current can be selected to be positive or negative, with the option of automatic reversal to eliminate the effect of thermal E.M.F.'s.

Micro Ohmmeter Control functions

• 6 measuring range controls (manual selection)

• AUTO key for auto range

• High/Low current control

• 3 Current direction measurement controls.
  + direction
  - direction
  Alternate (automatic reversal of + and -to eliminate thermal e.m.f. errors in measuring circuit) Supply ON/OFF

• Measure key

• Print key

• Calibration (CAL) control. Enables instrument internal reference standards to be calibrated by applying a set of external reference standards

• Menu/Enter key to access additional functions

• Time and date

• Print mode

• Baud rate

• Data logging mode

• RS232 for data and printer output

• 4 large 100A rated input terminals

• Mains input charging socket

• 2 battery charge indicators

Precision Micro Ohmmeter measurement principle

A four terminal measurement principle to eliminate lead resistance
The 100A current is pulsed with a duty cycle of approximately 10%. Measurement value displayed continuously

Power supplies

Two internal, re-chargeable, sealed, lead acid batteries are fitted for external 100A test resistance current and internal measurement supply circuits
Two charge indicators show the state of charge. The built-in battery charger has a front panel mains input supply for 115v or 230V supply with fuses 

Digital display

A 4 digit 4000 count display provides resolution to 0.025% of full scale reading in a bright daylight viewing 20mm high LED display

Mechanical

A rugged, portable sealed ABS case, colored gray

Size   460 x 380 x 160 mm

Net Weight Approx 17Kg

Calibration

Provided with an in-house Tinsley Calibration Certificate traceable to National Standards via NPL

Precision Micro Ohmmeter specifications
Range	Resolution	Current	Accuracy		Temperature Coefficient (%reading + last digit)
			% reading	Last digits
400µΩ	0.1 µΩ	100A/25A	+/-0.4%	+4	(0.04% +0.2)/ °C
4000µΩ	1.0 µΩ	100A/25A	+/-0.2%	+4	(0.02% +0.1)/ °C
40mΩ	10 µΩ	10A/2.5A	+/-0.2%	+4	(0.02% +0.1)/ °C
400mΩ	0.1 mΩ	1A/0.25A	+/-0.2%	+4	(0.02% +0.1)/ °C
4Ω	1.0 mΩ	100mA/25mA	+/-0.2%	+4	(0.02% +0.1)/ °C
40Ω	10 mΩ	10mA/2.5mA	+/-0.2%	+4	(0.02% +0.1)/ °C