DET5/4D & DET5/4R Digital Earth Tester DET5/4D & DET5/4R Digital Earth Tester n Simple, fully automatic operation n Choice of three or four terminal measurement n Autoranging from 10 m to 20 k n Tests to BS7671, BS7430, BS6651 and VDE 0413 n High tolerance to spike resistance helps testing in urban areas n Noise rejection to 40 V Each instrument is built into a small, lightweight case with DESCRIPTION a handle that has been designed for outdoor use and has The Megger DET5/4D and DET5/4R are fully automatic, IP54 protection. Four large terminals allow either spade or four terminal instruments built into a rugged, water hook connectors, 4 mm plugs or bare ended wire to be resistant case giving protection for outdoor use. The used for the test leads. Terminal Shorting bars are instrument is suitable for the testing of earth electrodes provided for continuity testing or measurement using the and measuring earth resistivity. dead earth method. A removable cover allows access to the battery compartment in the DET5/4D or to the charger Operation is started by pushing one of two buttons on the socket in the DET5/4R. front panel one for three terminal measurement and one for four terminal testing. All other functions of the instrument are completely automatic. The instrument APPLICATIONS checks for conditions that may cause an invalid reading The DET5/4D and DET5/4R digital earth testers are during a test. The low service error and wide operating reliable instruments able to measure the earth resistance of temperature range enable accurate results to be achieved both simple and complex electrode systems. They may be in real on-site conditions. used to test in accordance with BS7430 (1991), BS6651 There are four ranges covering measurements from 10 m (1992) BS7671 (the 16th Edition of the IEE wiring to 20 k. The earth resistance reading is displayed regulations), NFC15-100, IEC364 and VDE 0413 part 7 quickly, accurately and directly on a large, clear 312 digit (1982). The instruments are suitable for soil resistivity liquid crystal display. The display indicates when there is a measurements which are used to establish the optimum high test spike resistance and also when the noise earth electrode system design and location, to avoid interference is too high to take a valid reading. If the expensive reworking of electrical installations. They are batteries need replacing or recharging this will also be also suitable for performing archeological and geological shown on the display. investigations. Six 1,5 V AA dry cells provide power for the DET5/4D The direct indication of excessive noise and high spike allowing 600 typical 15 second tests. The DET5/4R is resistances avoids measurement errors and lengthy testing powered by an internal rechargeable, lead acid battery. of these parameters. The direct digital reading is This instrument has a built in battery charger that can unambiguous, avoids errors and assists in faster, more operate from a wide range of mains voltages. The capacity economic testing. of the lead acid battery enables 600 typical 15 s tests to be Earth testing kits including test spikes and leads, and a made from one charge.DET5/4D & DET5/4R Digital Earth Tester book describing several testing techniques are also SPECIFICATIONS available. Earth Resistance Ranges (Autoranging) 20 Range: 0,01 to 19,99 FEATURES AND BENEFITS 200 Range: n Simple to use, one touch operation 0,1 to 199,9 n Auto switch off to save battery power 2 k Range: n Rugged, weatherproof case 0,001 k to 1,999 k n Large, clear L.C.D. 20 k Range: 0,01 k to 19,99 k n Noise rejection to 40 V n Indicators show if reading may be invalid Accuracy (at 23C) n Terminal shorting bars supplied 7.5% 3 digits (10% at >0.5 ohms and 0.05 ohm at <0.5 ohms for KEMA K85B requirements. n Earth testing kits available n Optional carrying case and harness Maximum service error 7.5% 3 digits (10% at >0.5 ohms and 0.05 ohm at <0.5 ohms for KEMA K85B requirements. Display 312 digit L.C.D. with , k and low battery voltage indicators. LEDs for high noise, high voltage probe resistance and high current loop resistance. Test Frequency 128 Hz 0,5 Hz Test voltage Maximum 50 V peak Test Current (constant current within a range) 20 Range: 10 mA a.c. r.m.s. 200 Range: 1 mA a.c. r.m.s. 2 k, 20 k Range: 100 A a.c. r.m.s. Potential Circuit Interference Voltages of 40 V pk to pk at 50 Hz, 60 Hz, 200 Hz or 1623 Hz in the potential circuit will have a maximum effect of typically 1% on the reading in the 20 to 2 k ranges. If the NOISE LED is not showing, the maximum error due to noise on these ranges will not exceed 2%. In the 20 k range this is reduced to 32 V pk to pk. Current Loop Interference Voltages of 60 V pk to pk, 50 Hz, 60 Hz, 200 Hz or 1623 Hz in the current loop will have a maximum effect of 1% on the reading with minimal current loop resistance. Maximum Current Loop Resistance An additional error of typically 1% may be introduced for current loop resistances of:- 20 Range: 4 k 200 Range: 40 k 2 k, 20 k Range: 400 k