Digital micro-ohmmeter

The ruggedly designed digital micro-ohmmeter, the DO7, is a veritable workhores, ideal for use in the workshop, field or test facilities. Sealed in an ABS plastic case, the DO7 has built in rechargeable batteries which allow one hour's continuous use on the lowest ranges, and up to 20 hours on the others.

The DO7 is ideal for a range of resistance measurements in cluding:

Rotating machinesSwitch contactsElectrical connectorsCrimped jointsPCB trackCable Joints

Earth bondingSmall transformer windingsHeating elementsQuality of wrapped jointsQuality of solder jointsCable Lengths

True 4 wire measurements eliminate lead resistance errors

6 push button ranges 600 µO.. 60O

Resolution of 0.1 µO on 600 µO range

0.8" LED display, daylight viewable

10 amp measuring current

Input protection to 415 Volts rms

Forward and reverse current measurement

Auto average of forward and reverse measurement

Digital calibration, key protected

Mains rechargeable with battery state indicator

Technical Data

This portable Digital Ohmmeter is a practical instrument for low resistance measurement, ideal for use in the workshop, field or test facilities. It is of rugged construction, contained in a sealed ABS plastic case with lid and carrying handle.

The DO7 has many advanced features, including protection up to 415 volts rms at the measuring terminals, digital calibration and long scale length 6000 count. Rechargeable batteries means real portability with more than 1 hour's continuous operation on the lowest ranges and 20 hours on all others.Battery charge indicators are provided. The internal charger will boost charge to 90% of full charge, switching automatically to a trickle maintenance charge. Warning LEDs illuminate when an open circuit lead condition is detected.

A front panel soket provides a serial RS232 output for connection to an external printer or PC, and a socket is also provided for the connection of an external start switch, eg. a foot switch

The DO7 is supplied ready for use with batteries, mains cord and test leads - no extras are normally necessary, For special lead sets we offer a variety of different styles which are listed in this leaflet, together with calibration standards.

Range

Resltn.

Typical Current

Uncertainty @ 20°C ±5°C, 1 year

Temperature Coefficient / °C

60 O6 O600 mO60 mO6 mO600 µO

10 mO1 mO100 µO10 µO1 µO0.1 µO

1 mA10 mA100 mA1 A10 A10 A

±(0.15% Rdg + 0.05% FS)±(0.15% Rdg + 0.05% FS)±(0.15% Rdg + 0.05% FS)±(0.15% Rdg + 0.05% FS)±(0.2% Rdg + 0.1% FS)±(0.2% Rdg + 0.2% FS)

40 ppm Rdg + 30 ppm FS40 ppm Rdg + 30 ppm FS40 ppm Rdg + 30 ppm FS40 ppm Rdg + 30 ppm FS40 ppm Rdg + 30 ppm FS40 ppm Rdg + 250 ppm FS

Measurement4 Terminal Kelvin/Thomson principle eliminates error due to lead resistance. Open circuit measurement voltage, ~2V dc.

Display0.8" LED 6000 count with automatic decimal point and polarity indication.Ranges6 Push button selected with LED indication.CalibrationDigital, security key protected.Protection415 rms maximum at in put terminals.

BatterySealed lead acid, rechargeable cells giving a minimum of 1 hour's continuous measurement on the lowest 10 amp renges and 20 hours on all other ranges. Internal charger with battery state indicator.

Terminals6mm binding posts accept spade tags and 4mm banana plugs.

Working Temp0... 40°C rel. humidity 80% max. non-condensing.

Storage Temp-20... + 50°C

Mains Supply100/120/220/240/ Volts + 10% -13% 47... 63Hz. max 80VA

SafetyIEC 348 Protective Class 1.

Dimensions343 x 327 x 152 mm (W x D x H)

Mass8kg approx.

AccessoriesSupplied complete with mains cord, measuring leads with Kelvin Clips, handbook, and certificate of conformity.

External Start Foot Switch (FS01)Foot switch with 2 metre connection lead for connection to the external start socket.

Portable printer (PR01) Portable thermal printer with rechargeable batteries, supplied complete with connection cable.

Additional Lead SetsLS01 Duplex lead set with 3 metre lead length.LS02 Duplex lead set with 3 metre lead and 15 metre lead length.LS03 Large Crocodile style Kelvin clips with 3 metre lead length. LS04 Large crocodile style Kelvin clips with 3 metre lead and 15 metre lead lengths.