The MEGGER® Series 1-5000 instrument combines manual and automatic insulation testing. It performs manually controlled insulation tests at 500 V. 1000 V. 2500 V or 5000 V d.c. Also available are two automatic, standard insulation testing techniques, 'Polarization Index' (T.I.) testing and 'Step Voltage' testing. For 'Step Voltage' testing five equal steps up to 2500 V or 5000 V are used.

The instrument is microprocessor controlled which allows a variety of tests to be carried out simply. One rotary switch selects the function. the other selects the test voltage range; the display indicates the functions or ranges of each switch position. Adjacent to the display is a tactile key-pad with four small keys used to adjust the display's contrast and level of back light.
The large dot-matrix L.C.D. shows the measured value together with other relevant details about a test. For example, in basic testing, the nominal test voltage, the actual voltage across the resistance under test and the elapsed time duration of the test are shown. More comprehensive results are given by the enhanced testing options which include, graphical representations of the measurement, a useful feature when the test item is capacitive in nature, and the ability to measure the capacitance of the test item up to 10 pF.

Power Is supplied from an internal rechargeable battery or directly from a mains power source. The battery
can be charged while the instrument continues to be used.
The 'H* (high), 'L' (low) and 'G' (guard) terminals have shrouded sockets and a safety locking device for the test leads connectors. The guard circuit is extremely efficient enabling measurements of several Gigohms to be made with parallel resistance (leakage paths), as low as 250 ka

Up to 25 complete sets of test results may be stored in memory and retrieved for display on the screen, or, via an RS232C output, sending to a printer or external computer for further processing.
The instrument is capable of presenting the test results in a variety of ways and in any of four languages. It is possible to pre-select only those functions, ranges and options of interest of the operator, therefore the degree of complexity of the instrument can be suited to a particular requirement or level of operator understanding.

Operator safety is enhanced by separating the instrument's measuring and control circuits using an isolating transformer and internal optical fibre data links. The instrument is portable by either a handle or carrying strap and is built into a tough, robust case incorporating a test lead storage compartment.