Short Answer: Turn off the cathodic protection system for the time of the survey. See more details below.
Long Answer: The SuperSting™ and MiniSting™ may freeze or lock up at sites with very high stray voltages injected by cathodic protection (CP) systems. Cathodic protection is often running near pipelines, tank farms or other large metallic infrastructure.
The best solution is to turn off the cathodic protection system for the time of the survey. There is typically a circuit breaker box nearby with a simple on/off lever to do this. Many cathodic protection systems are turn-key and will restart on their own if turned off and then on later. Please check with the operators of the CP system for more details. Once the CP system is off, perform these two or three additional tests to clear your electronics before proceeding with measurements:
Additional Tests:
First, set your device to its Factory Default: Turn on the SuperSting™ > On the Main menu, press 6 > Press 4> Press 4 again. You should see Factory and Done on the line items in this last menu.
Next, add your SwitchBox under Menu 6—as this is removed during the factory default. (Note: If you are measuring 1D/VES, Wenner 4 pin/ASTMG57 or Manual Schlumberger, etc. you will not have a SwitchBox)
- Run a Receiver Test (Instructions for Pre-2016 models) (Instructions for all other models)
- Run a Switchbox Relay Test
- Check Batteries and/or Generator Power Supplies
Why would this problem occur?
The SuperSting™, in particular, is sensitive to the microvolt level of received signal. This level of sensitivity is necessary to achieve very long electrode spacing—needed for deep measurements. Because of this sensitivity however, electronics in the device can be overloaded.
CP is typically used at tank farms, pipelines and other areas with high amounts of metallic infrastructure that need to be protected from corrosion. CP systems may inject current momentarily, so the problems encountered can also come and go based on when you press measure or run your command file.
There are INOVL and TXOVL protections and warning beeps you may see flashing on the screen if cathodic protection is operating at your site.