Four-Arm Caliper HC-454
Four-Arm Caliper is one of the basic probes used for finding up technical state of boreholes.
It is mainly used for:

- establishment of diameter changes along borehole profile
- borehole volume calculation
- identification of hard and soft formations
- location of cracks, fissures or casing defects
- correction of other wireline logs for borehole size effects
Probe Parameters
Each arm measures independently.
Diameter | 45 mm |
Length | 150 cm |
Weigh | 8.0 kg |
Max. Working Temperature/Pressure | 75°C/10 MPa |
Min. No. of Cable Conductors | 4 |
Supply Voltage Range | 30 – 45 VDC |
Max./Nominal Current Consumption | 100/60 mADC |
Measuring Parameters
Measuring Range | 45 to 300 mm (short arms) |
100 to 700 mm (long arms) | |
Sensitivity | ±0,2 resp. 0,5 mm |
Communication (negative pulse) | 0 – 10 000 cps |
Special orders
Calipers of different diameters and different arm lenghts can also be manufactured upon special order. Their parameters are similar to those stated above.