Cropico DO4A Portable Milliohmmeter

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 an aluminium case with tilt handle.

The Cropico DO4A has many advanced features, including protection up to 415 volts rms, digital calibration and long scale length, 4,000 count. The rechargeable sealed lead acid battery means real portability with more than 14 hours continuous operation, without the problems normally associated with other battery types. Full measurement capability is maintained whilst charging.

Simple push button selection of the range required ensures the DO4A may be easily used by unskilled personnel, error and status warnings are illuminated when appropriate. The utmost care has been used to ensure that the ohmmeter will withstand an accidental mains voltage applied to the measuring terminals, but it is not recommended that voltage should be applied.

The measurement is true 4 terminal, using the Kelvin principle. A stable current is produced across the resistance to be measured via the C terminals, and the voltage drop across the Rx is measured at the P terminals. This potential drop is then compared against the voltage drop across internal standards, the ratio of these is then converted to the resistance value of Rx and displayed in ohms on the digital display.

FEATURES

True 4 wire measurement eliminates lead resistance errors.
6 push button ranges 40mΩ - 4kΩ with long scale length.
10μΩ resolution on 40mΩ range.
Input protection up to 415Vrms.
Zero control thermal E.M.F. compensation.
Digital calibration.
Mains/rechargeable battery operation.
Open circuit lead warning.
Rugged industrial maintenance free design.