Megger DET4 Four-Terminal Earth/Ground Resistance Testers
- Essential for soil electrical resistivity and earth resistance testing
The Megger DET4 Ground Tester is a robust and easy-to-use instrument designed for both soil electrical resistivity testing and earth resistance measurements. This versatile instrument serves two primary purposes: First, it helps you thoroughly check existing earthing systems. Second, it assists in the crucial design phase for new ground electrodes. The DET4 provides accurate results reliably, even in challenging weather conditions.
Why Choose the Megger DET4?
- Specifically engineered for soil electrical resistivity testing using the widely accepted fall-of-potential method.
- A true soil electrical resistivity tester that also handles 2-pole, 3-pole, and 4-pole ground resistance testing with precision.
- As a Megger Earth Tester, it meets CAT IV 100 V safety standards and boasts an IP 54 rating for robust outdoor use.
- Available in two convenient models: the Megger DET4TD2 (dry-cell powered) and the Megger DET4TR2 (rechargeable).
- Each instrument supports the essential job of measuring soil resistivity and ground resistance with exceptional ease.

Key Features of the Megger DET4 Family
- Performs soil electrical resistivity testing using the accurate 4-terminal (Kelvin) method.
- Serves as a reliable soil electrical resistivity tester and a precision Megger Earth Tester.
- Easy one-button operation with automatic checks for P-stake, C-stake, and noise levels.
- Measures resistance across a wide range, from 0.01 Ω up to 20 kΩ.
- Rejects ground noise effectively, up to 40 V peak-to-peak.
- Offers selectable output voltage (25 V or 50 V) at a 128 Hz frequency—fully compliant with IEC 61557-5.
- Its IP 54-rated case ensures protection against dust and water spray, making it ideal for rigorous field work.
- Features a large rotary selector that‘s easy to operate, even when wearing gloves.
- A clear LCD display simultaneously shows status, battery level, and measurement readings.
- As a trusted Megger DET4, it offers outstanding performance and strong build quality. It comes with all necessary accessories in one compact, ready-to-use kit.
Understanding Soil Electrical Resistivity & the Tester‘s Role
Professionals commonly refer to it as soil electrical resistivity testing because the instrument measures how well soil conducts electricity. For design purposes, knowing the soil‘s resistivity is crucial for correctly sizing earthing electrodes and grounding grids. This instrument excels as a soil electrical resistivity tester—it utilizes a four-terminal arrangement (C-P-P-C) to ensure uniform current flow and highly accurate readings.
The Megger Earth Tester DET4 series was purpose-built for both resistivity testing and grounding measurements. Its 4-terminal measurement capability is critical for accurate soil electrical resistivity testing, particularly when planning grounding systems or evaluating site soil conditions.
Model Options: DET4TD2 vs DET4TR2
Megger DET4TD2 – Part Number 1000-347
- Powered by dry-cell batteries (eight AA alkaline cells).
- Basic kit includes: DET4TD2 tester, four test leads (15 m, 10 m, 10 m, 3 m), four spikes/stakes, bare-wire terminal adaptors, a calibration certificate, and a rugged carry case.
- Measures resistance from 0.01 Ω to 20 kΩ for ground testing.
- Ideal if you prefer the convenience of disposable alkaline batteries for easy replacement in the field.
Megger DET4TR2 – Part Number 1000-324
- Powered by rechargeable AA NiMH batteries (eight rechargeable cells) with a built-in charger and AC/DC adaptor.
- Includes the same kit contents: leads, spikes, case, plus the bonus built-in charger system.
- Delivers the same excellent measurement performance: 0.01 Ω to 20 kΩ resistance.
- Perfect when you desire the economy and environmental benefits of recharging and want to avoid frequently buying disposable cells.
Technical Data Summary
Feature | Details |
Part number | 1000-347 / 1000-324 |
Power source | 8× AA alkaline dry-cell / 8× AA NiMH rechargeable |
Charger included | No / Yes (external AC/DC adaptor) |
Resistance range | 0.01 Ω to 20 kΩ |
Measurement accuracy | ±2 % ±3 digits (2-, 3-, 4-pole) |
Noise rejection | Up to 40 V p-p |
Output voltage | 25 V or 50 V at 128 Hz |
Earth voltage range | 0 to 100 V ac |
IP rating | IP54 |
Safety rating | CAT IV 100 V (with rated leads) |
Display | 3½-digit LCD |
Weight & size | ~1 kg, 203×148×78 mm |
Practical Use: Performing a Soil Electrical Resistivity Test
- Assemble the test stakes in a straight line, separated by the correct distances.
- Connect the test leads to the current and potential stakes in a C-P-P-C arrangement.
- Turn the selector switch to 4-pole mode and press TEST once.
- The instrument automatically checks P-stake and C-stake resistance and ground noise levels.
- It then outputs a test voltage (25 V or 50 V) at 128 Hz.
- Read the resistance value directly from the display. Use this measured resistance to accurately calculate soil resistivity using standard formulas.
- Because this is a high-performance soil electrical resistivity tester, it provides accurate readings essential for designing robust earthing systems or calculating optimal electrode spacing.
Benefits & Applications
- A trusted Megger Earth Tester for electricians, engineers, and safety professionals.
- Ease of use: Features one-button operation, glove-friendly controls, and automatic checks for streamlined workflow.
- Field-ready: With IP54 protection and a clear battery display, it‘s built for outdoor environments.
- Accurate in noisy environments: Thanks to superior noise rejection capabilities and selectable frequency.
- Suitable for: Lightning protection design, telecommunication mast earthing, grid layout surveys, and soil resistivity mapping.
- Ideal for both one-off installation testing and regular maintenance checks.
❓ Frequently Asked Questions (FAQ)
Q1: What is the difference between Megger DET4TD2 and Megger DET4TR2?
A. The primary difference is the power type. The Megger DET4TD2 (part number 1000-347) uses disposable AA alkaline cells, while the Megger DET4TR2 (part number 1000-324) uses rechargeable NiMH cells and includes a built-in charger and adaptor. Both models perform identically for soil electrical resistivity testing and ground resistance measurements.
Q2: Can I perform soil resistivity testing with these models?
A. Yes. Both models are designed as capable soil electrical resistivity tester instruments, fully supporting accurate four-terminal (4-pole) testing from 0.01 Ω to 20 kΩ.
Q3: Can it handle noisy environments?
A. Yes. The Megger Earth Tester DET4 series effectively rejects earth noise up to 40 V peak-to-peak. It also features selectable output voltage (25 V or 50 V) to suit various site conditions and minimize interference.
Q4: What do IP54 and CAT IV 100 V mean?
A. IP54 indicates the device is protected from dust ingress and water spray—making it highly suitable for outdoor field use. CAT IV 100 V is the highest safety category for low-voltage measurements, signifying it‘s safe for direct connection in power distribution networks when used with rated leads.
Q5: Do I need optional clamps or accessories for soil resistivity?
A. No. For performing a standard soil electrical resistivity test, the kit‘s included leads and spikes are sufficient. Optional clamps (I CLAMP and V CLAMP) are only required with the DET4TC2 and DET4TCR2 models to enable ART (attached rod technique) or stakeless testing—but these are not necessary for basic soil resistivity or ground resistance measurements with the DET4TD2/TR2.
Summary
The Megger DET4 series offers a powerful combination of reliability, accuracy, and ease-of-use. As a dedicated soil electrical resistivity tester, it enables you to perform a soil electrical resistivity test that is vital for informing proper earthing design and safety assessments. As a high-performance Megger Earth Tester, it measures ground resistance accurately, even in challenging conditions.
Choose the Megger DET4TD2 (1000-347) if you prefer alkaline batteries, or the Megger DET4TR2 (1000-324) if you prefer rechargeable cells and a built-in charger. Both kits include everything you need to get started immediately.
The Megger DET4 is the ideal instrument for contractors, consultants, and engineers who demand trusted results in every soil condition.
Megger DET4 TD2/TR2 Battery Options:
DET4TC2: Dry-cell battery powered 4-terminal tester with selectable test frequencies, greater measurement sensitivity and attached rod technique and stakeless measurement capability
DET4TCR2: Rechargeable battery powered 4-terminal tester with selectable test frequencies, greater measurement sensitivity and attached rod technique and stakeless measurement capability
- (1000-347) Megger DET4TD2 with Case, Basic Lead and Spike Kit, and Terminal Bare Wire Adaptors.
- (1000-324) Megger DET4TR2 with Rechargeable, Digital Display with Case, Basic Lead and Spike Kit, and Terminal Bare Wire Adaptors.

Megger DET4 Compatible Earth Test Cables and Spikes Kits:
ETK30, ETK50, ETK50C, ETK100, ETK100C