Model DPM Digital Potential Meter by M.C. Miller

For Cathodic Protection Potential Testing

The DPM voltmeter (Digital Potential Meter) is designed for ease of use by meter readers and corrosion technicians alike.  The voltmeter includes an integrated RE-5 reference electrode attached for "metallic structure-to-soil" potential difference readings.  The kit also includes a test lead for electrical connection to a metallic structure.

The voltmeter offers two ranges, ±2 VDC and ±20 VDC with a 20 MΩ input impedance.  Since the voltmeter is digital, both negative and positive voltages are displayed.

  • RE-5 reference electrode
  • 8’ red test lead with 46C clip

An optionally available electrode extension can be used to eliminate having to bend over to have the reference electrode placed in contact with soil.  See the M.C. Miller 30 inch Electrode Extension.

Digital Voltmeter:
  • Large 1/2" LCD digits.
  • Weatherproofed neoprene gasket.
  • 20MΩ input resistance.
  • Solid state impedance amplifier.
  • Operates on one small 9V battery, low drain - long shelf life, battery easily replaced and readily available.
  • Automatic low-battery indication on display.
  • Push one button to read +2V; push two buttons to read +20V while taking reading.
  • Digital readout: +1.999V or +19.99V.
  • Filter eliminates errors caused by AC, up to 50 volts, 50/60 Hz.
  • Operating temperature: -4°F to 185°F (-20°C to 85°C)
  • Molded poly-carbonate housing.
  • Plastic carrying case with resilient padding.
  • Modular construction.
  • Weight: about 3.0 pounds (1.36 kg)
  • Size: 2.5 inches (6.35 cm) deep x 10.0 inches (25.4 cm) long.


Ordering Information

Model DPM (Catalog No. 4110) includes the potential meter, RE-5 CuSO4 reference electrode, one 8' test lead with hippo clip, one 8' test lead with 27-C test clip, battery, protective cover for meter, and carrying case. Shipped assembled in case.

Warranty: Any part which fails during first six months (except battery), even if caused by overloading, will be repaired or replaced by MC Miller Co. without charge, when returned to MC Miller Co. prepaid and insured.


Optional Accessories



Intermediate Electrode Extensions, 30" and 15" long. One or more can be used with MCM Model ETM, IA and LC series meters, or between the electrode and the standard electrode extension so that the electrode can be easily placed at the desire location inside manholes, water tanks, etc. Will fit through a 1" diameter augered hole.

Anti-freeze Solution 

For use with any MCM Electrode. Permits potential measurements with temperature as low as -10oF (-23oC) without danger of cracking electrode tube. Can be used year round. 

The 8 oz (240 ml) bottle of Antifreeze Solution should provide approximately 6 refills for RE-5 and RE-5C electrodes. 

                #17105 - 8 oz                 #17207 - 32 oz

Copper Sulfate Crystals

The 40 oz bottle contains 2.5 lbs (1.13 kg) of crystals and should yield approximately 40 charges of Copper Sulfate crystals for RE-5 and RE-5C electrodes.
#16906 - 12 oz  #17003 - 40 oz  

 AGRA Reel 

 # 30501
(wire supplied separately)