Series: Reading the Receiver: What Are the Numbers Telling You?

by Allan Williams, Training Development Manager | GeoPoint Academy

Depending on the receiver you’re using, there can be quite a few numbers on the screen.

Signal strength. Gain or sensitivity. Frequency. Depth. Current. Battery level. Some receivers display even more.

Different manufacturers don’t always present that information the same way.

For a newer locator, it can be difficult to know which numbers deserve attention throughout the locate and which ones simply tell you how the receiver is currently set up.

Frequency is obviously important. You need to know what frequency you’re receiving and make sure it matches what you intended to use.

Gain or sensitivity helps control how the receiver presents the signal. Depending on the equipment, that may be shown as a number, percentage, decibel value, or another relative scale.

Signal strength gives you information about the response being received.

Personally, I tend to pay more attention to the Peak bar than the actual signal-strength number. I’m watching how that response behaves as I sweep across the conductor and as I continue along the locate path.

There really isn’t one universal signal-strength number that tells you everything is good. Receiver model, gain, frequency, depth and field conditions can all affect what you see.

What gets my attention is change.

If the signal has been behaving consistently and suddenly becomes noticeably stronger or weaker, I want to know why.

Depth is another useful piece of information. I’m not suggesting that a technician should constantly watch the depth reading, but an unexpected change should make sense with what’s happening along the locate.

If it doesn’t, take another look.

Then there is current, usually displayed in milliamps on receivers that provide it.

This is one I teach technicians to pay attention to as they trace.

I’m interested in the trend. A noticeable change in current can provide another clue that something along the locate path has changed. It can also be useful when verifying or troubleshooting a signal.

I saw a good example of this in the field.

A technician was tracing a power line that ran fairly close to a phone line. At one point, the power turned toward a pole while the phone continued straight ahead.

The receiver gave him more than one indication that something had changed.

The directional information changed.

The milliamp reading changed.

The depth reading changed.

He missed all of them because he wasn’t paying enough attention to the receiver.

He continued straight ahead and began tracing the phone line without realizing that he had left the power.

The receiver was giving him useful information. The important part was recognizing the change.

That example is one of the reasons I encourage technicians to become familiar with everything their receiver can display, even though they may not watch every value with the same level of attention.

Some readings tell you how the receiver is set up. Others help you follow what is happening as you move along the locate.

The better you understand those readings, the easier it becomes to notice when something changes and deserves a closer look.