20 Ohm Range Checkout 1. Next press the 20 ohm range switch, you should see the 20 ohm range indicator LED illuminate. 2. Plug the red banana jack lead into the 10 Ohm reference resistor. 3. The meter's display should read about or approx. 10 ohms (again maybe ohms or even ohms). If the 10 ohm reference resistor check looks "OK" then the 20 ohm range is good.

1. Next press the 200 ohm range switch, you should see the 200 ohm range indicator LED illuminate. 2. Plug the red banana jack lead into the 100 Ohm reference resistor. 3. The meter's display should read about or approx. 100 ohms (again maybe ohms or even as high ohms). If the 100 ohm (reference resistor) check looks "OK" then the 200 ohm range is good. 200 Ohm Mid-Scale Range Check

1. Next press the 200 Kohm range switch, you should see the 200 ohm range indicator LED illuminate. 2. Plug the red banana jack lead into the 100 KOhm reference resistor. 3. The meter's display should read about or approx. 100 Kohms (again maybe KOhms or as high as Kohms is fine). If the 100 Kohm (reference resistor) check looks "OK" then the 200 Kohm range is good to mid-scale is "OK". 200 KOhm Midscale Range Check

1. Next press the 200 Kohm range switch, you should see the 200 ohm range indicator LED illuminate. 2. Plug the red banana jack lead into the 100 KOhm reference resistor. 3. The meter's display should read about or approx. 100 Kohms (again maybe KOhms or as high as Kohms is fine). If the 100 Kohm (reference resistor) mid-scale check looks "OK" then the 200 Kohm range is good to mid-scale is "OK". 200 Kohm FullScale Range Check

The AMPTEC 630ES measures DC resistance with a 4 Wire Kelvin technique. Two of the wires Current high and Current Low pass through the resistance under test in a current loop - as part of a failsafe constant current source with only 5 mA in the current loop. It doesn't matter if the test leads are longer with more in-series resistance or even if there is some contact resistance with the connection to the resistance under test, because the constant current source's compliance voltage works to maintain a constant 5 mA (on the 2.0 ohm range) flowing in the loop. The other 2 wires (Voltage high and Voltage low) sense the voltage drop across the "resistance under test" (i.e. a squib). No measurement error in the voltage leads - The voltage measurement is high impedance – This means,virtually no current is drawn in the voltage sense lead wires. With "virtually no current drawn, in the lead wires there is virtually "No voltage drop or No Voltage Drop error in the voltage sense wires. Conclusion – With 4 Wire Kelvin, long distance test leads do not create a measurement error as long as you have compliance voltage drive remaining in the constant current loop. If test resistance is too high for the range, the 630ES display flashes "Overrange" meaning out of compliance voltage.

This 630ES User Instruction Card – found in the lid of the unit (

Conclusion – After verifying the 200 Kohm range of the meter is "OK" the 630ES is ready to safely measure the resistance of squibs, explosive bolts and a variety of EEDs (electro- explosive devices. Do not forget the website for tech support The password protected tech library offers a variety of 630ES support related technical documents, manuals, schematics and more... THE END