uring the manufacture of wires, rails, cables and sector conductors, the electrical conductivity respectively the resistance must be checked for compliance with specified values. In conjunction with a digital ohmmeter of burster´s RESISTOMAT® series, the clamping devices are used in the cable industry for production monitoring and quality assurance. As most of the materials used have a very high temperature coefficient, e.g. copper 3.93 %/K, aluminium 4.03 %/K , a precise recording of the test unit´s temperature during measurement is of particular importance. Needless to say, the clamping devices described are equipped with 4-conductor technology, thus eliminating lead and contact resistances.
1 With the help of clamping device model 2381 and a milliohm- or microohmmeter of burster´s RESISTOMAT® series, the ohmic resistances of test cables and material samples in the shape of cords or strips can be measured. Fields of application include production monitoring, quality assurance and general test measurements. Model 2381 consists of a robust, warp-resistant, light-metal rail with one movable and one rigid clamping device. It allows the measurement of samples 50 to 1000 mm long. The clamping device is designed to accommodate cable cross-sections of 0.1 mm2 to approx. 100 mm2 . For larger cross-sections, the distances between current feed and potential tap must be increased in order to ensure a uniform current distribution. Adaptation to the diameter of the test unit is carried out through a coarse adjustment of the clamping jaws. The quick-action clamping device allows the test unit to be clamped rapidly and securely in one single movement. Optional Features The clamping device can always be supplemented with the guide rail model 2388 shown in the illustration. This rail offers major advantages. It serves as a support and guidance for the test samples. In addition, it offers protection against draughts, thus preventing rapid changes in the temperature of the test objects. These advantages are particularly noticeable in the case of small cross-sections which, due to their low heat capacity, react to the slightest draught. Although thin test units sag only minimally even without a guide rail, the increase in length due to this sag is often significant enough to cause errors in the measurement results. A sensor block is integrated into the guide rail. With the help of the temperature sensors model 2392 resp. 2391, the temperature of the guide rail resp. the sample material can be recorded and compensated appropriately by the measurement device. Technical Data Adjustable clamp support: measurement length of up to 1000 mm Test unit cross-sections: ranging from 0.1 mm2 to approx. 100 mm2 Current connections: designed for 100 A Potential tap: routed to 4 mm standard device terminals via material with low thermoelectric power Dimensions (height x width x depth): 1300 x 120 x 150 [mm] Weight: approx. 8.5 kg Order Information Clamping device Model 2381 Guide rail Model 2388 1 set interchangeable contacts for the potential tap Model 2390 Connection cable for RESISTOMAT® models 2304, 2320, 2323, 2316-V000X with 4 banana plugs, 2 m length Model 2381-K003 Connection cable for RESISTOMAT® models 2329, 2316-V000X with 5 pin bayonet plug, 2 m length Model 2381-K006 Clamping Device Model 2381-V001 The clamping device model 2381-V001 is designed for cross-sections of 1 ...1500 mm2 . The measurement length is 1000 mm. A uniform current distribution is ensured by the distance between current and voltage tap. The clamp support is laterally adjustable by means of a spindle so that the immersed test unit can be stretched. This is particulary advantageous in the case of large cross-sections. Technical Data Measurement length: 1000 mm Clamping device: designed for cross-sections of 1 ... 1500 mm2 (max. 44 mmø) option 2500 mm2 (max. 57 mmø) Distance between voltage tap and current feed: 420 mm Connection cable: 2 m length with 4 banana plugs Dimensions (H x W x D): approx. 190 x 2160 x 350 [mm] Weight: approx. 25 kg Order Information Clamping device Model 2381-V001 2381 EN - 2 Clamping Device Mode 2382 L The clamping device model 2382 L can be used to check during production or in the test bay the electrical conductivity respectively resistance of wires, rails cables or sector conductors for power cables. The measurement length is 1000 mm. The clamping device is designed for cross-sections of 1 ... 1500 mm2 . Detailed investigations and long experience have shown that particulary in the case of larger cross-sections, precise temperature measurement is only possible in a liquid medium. Model 2382 L is equipped with a water bath which temperature is controlled with an integrated thermostat. The integrated circulation pump ensures a uniform temperature distribution in the water bath. The specimen´s measurement length of 1000 mm is immersed entirely in a liquid medium (water). The digital ohmmeters of our RESISTOMAT® series correct the measurement value display automatically to the VDE value at 20 °C. A uniform current distribution has been ensured on fitting quick-action vices outside the bath. The clamp support is laterally adjustable by means of a spindle so that the immersed test unit can be stretched. This is particularly advantageous in the case of large cross-sections. Technical Data Measurement length: 1000 mm in a temperature-controlled water bath Clamping device: designed for cross-sections of 1 ... 1500 mm2 (max. 44 mmø) option 2500 mm2 (max. 57 mmø) Constant water temperature ensured by a two-position controller and an integrated circulation pump Precise temperature measurement with an integrated sensor Operating range: 25 °C ... 60 °C, tolerance ± 0.5 °C The distance between the potential tap and the current feed is 420 mm. This ensures an adequate current distribution even in the case of large cross-sections. Current connections: designed for 100 A Output of the integrated heating filaments: 2 kW Voltage supply: 230 V, + 6 % -10% Mains frequency: 50/60 Hz Power consumption: approx. 2.2 kVA Device protection: EN 61010 Weight (without water): approx. 85 kg Dimensions (H x W x D): 0.3 x 2.10 x 0.5 [m] without wire holder 0.3 x 1.33 x 0.5 [m] Order Information Clamping device Model 2382 L Clamping Device Model 2382 A This clamping device can be directly integrated in the stranding machine. A good fixation of the wire is therefore assured. So the clamp jaws, as included in the 2382 L, are not necessary. Technical Data See model 2382 L, but without clamp jaws. The measurement current connection happens directly by the stranding equipment. Order Information Clamping device