- Can I see the water table?
- Does saturation affect EC readings?
- Does contamination affect EC readings?
- What are the units displayed for EC?
- How far can the Wenner array see in the soil?
- Why use dipole?
- What does a bad probe log look like?
- Why does the isolation number keep dropping each hole?
- What is the excitation voltage?
- Why don't I get shocked?
- Why can’t I use my analog meter to measure the excitation voltage?
- 1. Can I see the water table?
- No. Porosity and materials makeup are the key elements to determining the electrical conductivity of a soil type. Moisture content can only compliment the value seen by a probe.
- 2. Does saturation affect EC readings?
- Saturation has some effect on EC readings. Saturation or moisture content impacts the probe signal only through improving probe contact with the soil. The Predominant component that affects electric log readings will be grain size. An exception is when pore fluid carries ionic contamination as in salts or brines.
- 3. Does contamination affect EC readings?
- Contamination will only affect the conductivity readings if in extreme high concentrations. Pore fluid can be contaminated by ionic compounds causing the EC readings to rise dramatically. In these cases, the conductivity is much higher than that of native soils, therefore it is easily identified.
- 4. What are the units displayed for EC?
- Milli-Siemens per Meter (mS/m)
- 5. How far can the Wenner array see in the soil?
- 3.5 inches
- 6. Why use dipole?
- When a pole or probe contact is lost to connection failure in the Wenner array (four pole), another pole combination can be selected setting-up a dipole array (two pole). Another place a dipole is used is on MIP or expendable EC probes.
- 7. What does a bad probe log look like?
- Where their would be expected changes in signal, there is a flatline being generated on the display.
- 8. Why does the isolation number keep dropping each hole?
- The isolation test on an Electrical Conductivity probe is a very sensitive test intended to check the insulation properties of the probe. Moisture, surface rust and dirt can cause the isolation test numbers to fluctuate. As long as the reading on isolation tests does not get below 10 kilo-ohms, all is well. In addition, probe wear over time can cause this number to drop.
- 9. What is the excitation voltage?
- 0.75 Volts AC
- 10. Why don't I get shocked by the excitation voltage?
- The excitation voltage is a low level AC signal. Signals at low levels like the one used on an Electrical Conductivity probe is not hazardous.
- 11. Why can't I use my analog meter to measure the excitation voltage?
- The excitation voltage is less than one volt AC and can be more accurately measured with a digital multi-meter.
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