- Test voltage
- 1 to 1000 V continuous on the wide-range model; 10 to 1000 V settable on the other
- Resistance range
- 500 Ω to 100 TΩ on the wide-range model; 100 kΩ to 1 TΩ on the other
- Current range
- 1 pA to 2 mA on the wide-range model; 0.001 to 200.0 µA on the other
- Accuracy
- 1% while resistance is below 10 GΩ and current above 10 nA; ±3% ±3 digits below 1 TΩ and ±8% ±3 digits above it on the other model
- Speed
- 40, 15 and 5 readings per second in three steps; about 6.7 per second on the other model
- Input resistance
- 10 kΩ or 1 MΩ, switchable, on the wide-range model
- Sorting
- Five comparator outputs, low, three bins and high; one pass or fail bin on the other model
- Storage
- 100 internal records and 500 on USB, on the wide-range model
- Display
- 480 × 272 colour screen; four significant digits on the other model
- Body
- 280 × 88 × 320 mm at 4 kg; 350 × 300 × 105 mm at about 3 kg for the other model
Two instruments under one page, and they are not two trim levels of the same thing. One is a fast wide-range meter built to sort parts on a line; the other is a conventional bench instrument that answers a single question. The choice between them is a choice of task.
Product overview
The wide-range model covers resistance from hundreds of ohms to a hundred teraohms, at a voltage that starts at one volt, with three speeds, five sorting outputs and six hundred stored records. It is a production and laboratory instrument in a half-rack case.
The conventional model covers a narrower resistance band at a fixed lower voltage limit, with a pass or fail judgement and optional interfaces. It is smaller, lighter and simpler, and it is the right instrument where the test is one point rather than a distribution.
Both apply a direct voltage, measure the leakage current and derive resistance from the ratio, and both provide open-circuit zeroing to remove the residual of the fixture.
How the meter works
The output is raised to the programmed voltage and the current that flows is measured. Resistance follows from the ratio, which means the highest resistance the instrument can report is set by the smallest current it can resolve, and the accuracy falls away as that floor is approached.
The wide-range model changes its input resistance between two values. That is not a range switch in the ordinary sense: it changes the impedance the instrument presents to the item, and therefore how quickly the charging current decays to the leakage level. A low input resistance charges a capacitive item quickly and gives a reading sooner; a high one draws less from the source and suits the top of the resistance range.
The three speeds trade time against noise. Averaging over more readings reduces the scatter on a high-resistance measurement, and the fastest setting is for a line where the pass limit is far from the reading and the scatter does not matter.
Sorting compares the result with stored limits and drives one of five outputs, so a handler can route a part to a bin rather than only stopping the line.
How to select the right model
Begin with the resistance band. A test that has to distinguish an open circuit from a good insulator at the top of the range needs the wide-range model, because the conventional one stops a hundred times lower.
Then the voltage. If the test has to run below ten volts, only the wide-range model reaches it. If the standard calls for a few hundred volts, both do.
Then the throughput. A line that tests every part needs the fast step and the sorting outputs; a laboratory that tests a sample needs neither, and the conventional model is the simpler purchase.
Then the interface. GPIB appears on one page and not on another, so a bench that is already wired for it has to have that point settled in writing before the order.
Measurement limitations and selection considerations
The accuracy figure is conditional, and the condition is the interesting part. It applies where the resistance is below ten gigohms and the current above ten nanoamps; outside that, the error grows because the current channel is working near its floor. A single percentage quoted without the condition would be true only in the middle of the range.
At the top of the range the measurement becomes an environmental one. Surface leakage, humidity, the insulation of the leads and the geometry of the item all contribute currents of the same order as the one being measured, and no instrument can separate them without a guard, shielded leads and a controlled environment.
Insulation resistance is not dielectric strength. This instrument measures leakage at a voltage below breakdown; a withstand test measures survival at a higher voltage. The two are separate tests, and a good insulation reading does not predict a withstand result.
The two models differ in size as well as capability, and the footprints are not interchangeable. A bench laid out for one will not necessarily take the other without moving what is around it.
Every value below is taken from source documentation. Where a parameter is not stated in the available material it is marked as information required rather than estimated.
