- Turns range
- 1 to 80,000 on CH1201 and CH1201R; 1 to 30,000 on CH1200 and CH1200R
- Turns accuracy
- ±0 turns to ±1 turn at the low end, then ±0.2% or ±0.3%, and ±0.5% at the top of the 80,000 range
- Turns speed
- 3 readings per second on CH1201; 1.5 on CH1200
- DC resistance
- 100 µΩ to 200 kΩ on CH1201R; 100 µΩ to 20 kΩ on CH1200R
- Resistance accuracy
- 0.2%, measured four-terminal
- Coil size
- Inside diameter above 4 mm, outside diameter below 120 mm, height below 110 mm
- Sensors
- Ø9.5, Ø6 and Ø4 mm, with Ø4 supplied as standard
- Display
- LED digital display
- Interface
- RS232C as standard
- Body
- 335 × 320 × 290 mm, about 6 kg
Counting turns by hand is slow, and counting them by eye is unreliable above a few hundred. A turns counter replaces both with a number on a display, and the useful questions are how large a coil it can take, how fine the count is at the low end, and whether the same station can also check the winding resistance.
Product overview
Four models share one case and one sensing head. Two count to 80,000 turns at 3 readings per second; two count to 30,000 at 1.5. Within each pair, the model with an R suffix adds DC resistance measurement through a four-terminal connection.
The case is 335 mm wide, 320 mm deep and about 6 kg, with the sensing rod rising from the top cover and the display, alarm keys and power switch across the front. Three sensor diameters are available, and the smallest is supplied as standard.
How the turns counter works
The coil is placed over the sensing rod, which couples the winding to the instrument. The number of turns is derived from that coupling rather than counted mechanically, so the coil does not have to be rotated and the count appears as soon as the part is in position. The instrument selects its range automatically, which is why there is no range switch and no calibration step before a measurement.
The sensing diameter has to suit the bore of the coil. A head that is too small for a large coil couples weakly; the material recommends the largest head when the inside diameter is above 30 mm. The coil also has to fit within the stated envelope: inside diameter above 4 mm, outside diameter below 120 mm and height below 110 mm.
On the two R models, the same instrument measures the DC resistance of the winding through a four-terminal connection, with separate current and voltage leads so that the lead and contact resistance stay out of the reading. That is what makes a result in the hundreds of microhms meaningful, and it is also the check that catches a winding made with the wrong wire gauge.
How to select the right turns counter
The first question is the largest turn count the bench will see. Thirty thousand covers most small and medium transformers and relay coils; eighty thousand covers larger machine windings. Buying the larger range also buys the finer low-end accuracy, since the 80,000 models are specified at zero error below 300 turns.
The second is whether resistance has to be measured at the same station. If the winding resistance is already checked elsewhere, the plain models are enough. If the count and the resistance belong to one operation, the R models remove a handling step, and the difference between them is the resistance range: 20 kΩ on the 30,000 model, 200 kΩ on the 80,000 model.
The third is the physical size of the coil. The envelope is fixed at 120 mm outside diameter and 110 mm height, and no model extends it. A coil outside that envelope needs a different fixture, not a different model.
The fourth is throughput. Three readings per second against 1.5 is the difference between keeping up with a winding machine and checking a batch afterwards.
Measurement limitations and selection considerations
The instrument counts turns on air-core coils and on transformer and motor windings. It is not intended for coils with a magnetic core or a magnetic ring, and the material states that parts below 4 mm in diameter which are magnetic cannot be tested at all. A magnetic core changes the coupling the count depends on, so the number is not merely less accurate — it is not meaningful.
The count is a number, not a diagnosis. A coil with the right number of turns and a shorted turn will still count correctly, and a coil wound with the wrong wire will count correctly as well. Those faults need a pulse test or a resistance measurement, which is the reason the R models exist and the reason a turns counter is usually one station in a line rather than the whole inspection.
The sensing head is a mechanical interface as much as an electrical one. A coil that sits loosely on the rod, or one whose leads cross the sensing area, will not repeat. The fixture and the way the operator places the part belong to the measurement.
Finally, the resistance reading is a DC measurement at low current. It says nothing about the AC resistance or the losses of the winding at the frequency it will actually run at, so a coil that passes the resistance check can still run hot.
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.
