The Megger DET4TD2 (1000-347) is a basic dry-cell battery powered 4-terminal tester. It is rated to IP54, making it truly an outdoor instrument. The DET4TD2 is designed to meet stringent safety standards and is rated CAT IV 100 V.

The DET4TD2 ground tester is easy to use: a large selector switch makes selection of 2, 3 or 4 pole tests easy with gloved hands. A clear, easy to read LCD and thumb-sized test button also makes the instrument particularly well-suited to the outdoor conditions of ground testing. In addition to this ease of use feature, the instrument automatically checks the connection and conditions of the P spike, C spike, and also the level of ground noise, indicating the status on its display. It also includes a voltmeter to enable measurement of ground voltage.

The DET4TD2 can measure resistance from 0.01 ohms to 20,000 ohms. To allow accurate testing in noisy environments, the instrument is capable of rejecting noise up to 40 V peak to peak.

The DET4TD2 is powered by eight AA batteries which are widely available and also give excellent testing time. The status of these batteries is given by a bar graph on the LCD display, allowing the operator to decide when to change the batteries before they expire.

The DET4TD2 tester has selectable 25 V or 50 V output for compliance with IEC 61557-5. The 25 V output is required for testing in agricultural environments.

The DET4TD2 can perform bonding tests (using an AC signal) to determine that an adequate connection has been made from equipment to the grounding system, and it can also perform soil resistivity tests. This additional function can be used in prospecting, locating, and designing new grounding electrodes and systems.