AMA Ohm Meter

 
AMA OHM METER :-
Conforming to IS 5780-1970 the equipment is suitable for checking resistance of circuit. 0-300 Ohms. Ohmmeter is approved by DGMS vide his intrinsically safe certificate No. 28 group 1. Also available in 0-600 Ohm and 0-1000 ohm range.

  
General :- Intrinsically safe Ohmmeter conforming to IS-5780. 1970 is developed primarily for testing the circuit, either for electrical resistance or for continuity before connecting to the firing apparatus. This intrinsically safe Ohmmeter can also be used for all other form of resistance testing. 

Approval :- 0-300 Ohmmeter is approved by DGMS vide his intrinsically safe Certificate No. 28 group I . 

Construction :- The meter is housed in elegantly polished teak wood/fiber glass body casing and provided with a leather carrying handle. Two terminals for shot firing cable leads, potentiometer for infinity adjustment and push button switch are conveniently located. A completely balanced and damped moving coil Provides 'dead beat' deflection and steady reading unaffected by the angle at which the instrument is held. The scale is marked 0-300 ohms with open reading between 0.50 Ohms. The tolerance of the Ohmmeter is well within 3 %. Independently accessible battery hold houses a 1.5V dry cell which is the input source. 

Infinity adjustment :- Before carrying out test for resistance the pointer should be set to INF (infinity) by pressing the push button switch and adjusting potentiometer screw. 

Circuit Testing :- 

a) Connect the two open end of the shot firing cable to the output terminals.
b) Press the push button. If the needle moves to INF and stays the line is open circuit and corrective step should be taken.
c) If the needle shows more then permissible resistance then all connection should be checked and re-twisted.

Also available in 0-600 Ohm and 0-1000 Ohm range 
 

 
Digital Ohm Meter

AMA DIGITAL OHM METER :-
 
Intrinsically safe digital ohmmeter is most suitable for testing blasting circuit for resistance and continuity before connecting to exploder. This intrinsically safe digital ohm meter can also be used for all other forms of resistance testing. The unit is housed in moulded plastic box. Two heavy duty terminal and push button switch are conveniently located. Resistance upto 9999 ohm can be measured.