The AEMC 4500 20k ohms 4 Point Ground Resistance Tester is designed for measuring very low resistance on large grounding systems, such as ground grids and ground mats. It rejects high levels of interference voltages at DC or 60 Hz and its harmonics, and can be used under difficult conditions such as high stray currents or excessive auxiliary electrode resistance without substantially affecting accuracy.
AEMC Instruments 4500 Features
- Measures soil resistivity (4-Point)
- Measures ground resistance (2 and 3 Point) Fall-of-Potential Method
- Step voltage tests and touch potential measurements
- Selectable: three test currents and five resistance ranges
- Measures very low resistance on large grounding systems and grids
- High test current also enables geological surveys
- Large easy-to-read LCD
- Display includes indicators for excess stray
- auxiliary rod resistance and fault connection
- Battery (rechargeable) powered or external 12VDC
- Rugged dustproof and rainproof field case
- Can be used for continuity tests on bonding
AEMC Instruments 4500 Specs
||20 k ohms
||1 m ohms
||10 m ohms
|Resistance Measurement Frequency
||128 Hz square wave
||2 mA, 10 mA, 50 mA
||±2% of Reading ± 1ct from 10% to 100% of range
|Auxiliary Electrode Resistance
||50 k ohms on 20 ohms, 200 ohms, 2000 ohms & 20 k ohms ranges; 5 k ohms on 2 ohms range
||2 mA range: 15 k ohms; 10 mA range: 3000 ohms; 50 mA range: 400 ohms
||The unit is designed to reject high levels of interference voltages at DC, or 50/60 Hz and their harmonics
|Noise Influence on Accuracy
||0.5% of range (max) to 20V peak
||Built-in rechargeable 12V, one Ah NiCD battery, or external 12 VDC; low battery indication. Battery can be recharged with built-in dual voltage charging unit:94 to 127V or 187 to 253V (47 Hz to 450 Hz)
||14 hours typical
|Charging Supply Voltage
||Internally selectable 110/220V, 45 to 450Hz
||Four hrs on 50mA test current (800 15 sec measurements),Seven hrs on 2mA and 10mA test currents (1500 15 sec. measurements)
||500 Vrms measurement circuit
AEMC Instruments 4500 Applications
- Three-point measurement of large grounding grids, counterpoises, ground mats and grounded equipment.
- Soil resistivity tests (4-Point measurement), commonly performed by utilities at proposed construction sites.
- Using soil resistivity analysis, the size and complexity of grounding system construction can be evaluated.
- The AEMC 4500 will measure the resistivity of epoxies, cement, ground enhancement materials and many other substances.
- Step or touch potential levels under true fault conditions can be determined by using the Model 4500 to inject a simulated low-level fault into an electrical system. When used in this fashion, the AEMC 4500 will display readings in volts per fault ampere.
- Two-point tests for continuity tests on bonding or on pre-established grounds.