The Biddle DET 2 Digital Earth Tester is a completely self contained instrument designed to give accurate measurements of earth electrode resistance, soil resistivity etc. It uses the reversing d.c. technique.
The instrument is housed in a robust insulated portable case, which being yellow in colour is easily visible from a distance. All the controls, the terminals and the liquid crystal display digital panel meter are mounted on the panel underneath the hinged cover. The instrument is splash proof and suitable for outdoor use in most weather conditions.
Specifications:
| Earth Resistance Ranges |
0,001 – 1,999Ω |
| 0,01 – 19,99Ω |
| 0,1 – 199,9Ω |
| 1 - 1999Ω |
| Accuracy (20°C) |
±2% of reading ±2 digits |
| Temperature Effect |
±0,1% per °C |
| Working Temperature Range |
-15°C to +50°C |
| Storage Temperature Range |
-30°C to +7C°C |
| Humidity |
95% A.H. combined with cyclic temperature changes of25°C to 40°C (BS2011: Part2.1, Db: 1977, IEC68-2-30: Test Db: 1969) |
| Test Frequency |
128Hz reversing d.c. |
| Interference |
Steady interference voltages at d.c., 50 or 60Hz will be rejected. The effect of transient noise is minimised by a switched filter. |
Maximum interference:-
2Ω range low current ± 5V peak
2Ω range normal current ± 10V peak
all other ranges and currents ± 20V peak |
| Filter Time Constant |
Normal (filter switch 'OUT') 1 second |
| Long (filter switch 'IN') 10 seconds |
| Test Current |
High 40mA |
| Normal 10mA |
| Low 5mA |
| Maximum Current Spike Resistance |
The maximum permissible resistance of the current loop depends on the test current selected:-
High current: 800Ω
Normal current: 3,5kΩ
Low current: 7,5kΩ |
| Maximum Potential Spike Resistance |
The input impedance between the potential terminals is - 2MΩ. A maximum potential loop resistance of·10kΩ will give an additional error of 0,5%. |
| Output Voltage |
50V maximum from the Cl, C2 terminals |
| Display |
3% digit l.c.d. maximum reading 1999 |