CRT-600A Contact Resistance Meter
CRT-600A
Measures the contact and loop resistance of circuit breakers, switchgear and joints at up to 600 A DC, with a four-terminal connection that keeps lead resistance out of the result.
Supplied and supported by GPS LTD, London · 1-year warranty
High current. Micro-ohm precision.
A high test current gives a more representative reading of a contact under load, overcoming the surface films that can distort a low-current measurement.
Four test currents
Choose 100, 200, 300 or 600 A DC. The current comes from a constant-current switching supply that needs no manual adjustment, so every test starts the same way.
Four-terminal accuracy
Separate current and sense leads keep lead and clamp resistance out of the result. Readings resolve 0.1 µΩ with an accuracy of 0.5% ±2 digits.
Print and store
Print a result on the built-in printer or store it with the date and time. Settings and results read clearly on an English dot-matrix display.
Four wires, one clear answer
Two thick leads carry the test current; two thin leads measure the voltage on the object itself, so only the resistance you want is measured.
- Current leads on the outer ends. Thick red lead from I+ and thick black lead from I−, both on the same conductor, tightened firmly.
- Sense leads inside them. Thin red lead from V+ and thin black lead from V−, on the object just inside the current clamps.
- Clean, firm contact. Every clamp face clean and in good contact; red to red and black to black.
- Resistance between the sense points. That is the part of the joint or contact the reading describes.
From settings to a printed result
Four keys and one settings screen: choose the current and duration, start the test, and read the current and resistance together.
Set the current
Select steps through 100, 200, 300 and 600 A; OK confirms and moves on.
Start the test
Choose the duration, highlight test and press OK.
Testing
The display shows the elapsed time and the test current as it is applied.
Read, save, print
Current and resistance together. Store saves the result; Select prints it.
Wherever a contact has to carry current
Breakers, switchgear and busbars
Contact and loop resistance of high and low voltage circuit breakers, isolators and busbar runs.
Cable, weld and bolted joints
DC resistance of cable connections, welds and bolted joints that must carry high current.
Maintenance and commissioning
Routine substation maintenance and commissioning checks, with printed results for the record.
Everything on one face
- 1Power input · AC220V terminals for the supply cord
- 2Power switch · circuit breaker, ON / OFF
- 3Earth terminal
- 4Printer · prints the result
- 5USB port
- 6RS232 port
- 7Display · 128 × 64 dot matrix
- 8Keys · Reset, Select, OK, Store
- 9I+ · current output
- 10V+ · voltage sense
- 11V− · voltage sense
- 12I− · current output
CRT-600A at a glance
| Test current | DC 100 A, 200 A, 300 A, 600 A |
| Measurement range | 1 – 1999 µΩ |
| Range by test current | 0 – 50 mΩ (100 A) · 0 – 25 mΩ (200 A) · 0 – 16 mΩ (300 A) · 0 – 8 mΩ (600 A) |
| Resolution | 0.1 µΩ |
| Accuracy | 0.5% ±2 digits |
| Method | Four-terminal (Kelvin) connection, constant-current DC from a switching supply |
| Test duration | Fast · 30 s · 1 min · continuous |
| Test time | Result displayed in about 8 s (fast) |
| Display | 128 × 64 dot-matrix LCD, English |
| Printer | Built-in, prints the test result |
| Data | Clock and data storage |
| Interfaces | USB · RS232 |
| Terminals | I+, I− current output · V+, V− voltage sense · earth terminal |
| Power | 6000 W |
| Supply | AC 220 V ±10%, 50 Hz · contact us to confirm the supply connection for your site |
| Working environment | −10 °C to 40 °C · ≤80% RH, non-condensing |
| Shipping | Carton 500 × 440 × 460 mm · 22 kg gross |
What’s in the box
- CRT-600AIn its aluminium carry case
- Test leadsThick current leads and thin voltage sense leads, red and black
- Power cord
- Earth lead
- Printer paper
Good to know
- Supply connection. The CRT-600A is rated AC 220 V ±10%, 50 Hz, 6000 W, connected on its power input terminals. Please contact us to confirm the supply connection for your site before ordering.
- Shipping. 22 kg gross, in a carton of 500 × 440 × 460 mm.
- Interfaces. USB and RS232 ports are fitted; ask us for details of their use.
- Documentation. The quick start guide covers connection, testing, saving and printing. Full instructions for stored results and settings are available on request.
- Ordering. Part number on request.