6
Maintaining & Checking Your Reference Electrode
Please consult M. C. Miller’s instruction manual titled, “How to Prepare and Maintain Portable M. C. Miller
Copper Sulfate Reference Electrodes”, which is Manual # 270, for details.
Structure-to-Soil (or to-Water) Potential Readings
Assuming that you have prepared both meter and reference electrode as detailed previously, measuring
a potential is very easy.
Remove the orange protective cap from the reference electrode. Place the lower end of the reference
electrode (the porous ceramic plug) in solid contact with soil or water at desired location. For best results,
there should be no vegetation between electrode and the soil.
Connect the clip end of the test lead onto the metallic structure being tested. Make sure that the contact
point with structure is clean and shiny.
Press and hold the 2V range push-button.
Read and record the voltage value obtained, unless the meter indicates “1.“, which indicates an over
range condition. Switch meter to 20V range by pressing and holding both push-buttons in such a case. If
the meter again indicates an over range, the input voltage exceeds 20V and cannot be measured by this
meter.
IMPORTANT: The polarity of a reading is a vital part of the reading and should always be
recorded along with the numerical value on your data sheet.
NOTE: Most potential readings will normally be negative and therefore the display will show a (-) minus
sign. If there is no minus sign displayed, the reading is positive, but no positive sign will be displayed.
