A milliamp clamp-meter can measure small electrical currents by simply clamping over a wire. This is especially useful in measuring the small pulses created by decoder activity on 2-wire irrigation circuits without undoing wire splices. Clamp-meters don’t have to be inserted in an electrical circuit to measure current, while conventional meters do.
Get the most basic meter you can, as long as it does what you need:
- Just checking batteries, clock volts or solenoid resistance: use a basic multimeter like the Pro30™,
- Measuring different electrical things like resistance, low or high voltage, and low or high current without much experience with meters: use an automatic meter like the Pro90™,
- Measuring a wide range of electrical currents with unusual characteristics (LEDs, decoders): use a sensitive true RMS meter like the Pro93™ or Pro95™.
A TDR is a kind of ‘wire radar’ with a graph screen showing responses from down a connected wire. It can show both the kind of fault and distance to a fault if set up correctly. It can tell you how long a cable is, whether it ends in an open circuit or short circuit, or whether there is a splice in the middle.
Broadcast mode is a locator feature that uses a case-mounted wireless tracking antenna. The locator is placed on the ground near the target wire. This is especially useful when you are not able to connect directly to a wire or when you only know the approximate location of a wire you want to track.
A good electrical ground through the locator’s ground stake is most important. In addition, common problems come from confused signals created by nearby cables, something that is often dealt with by moving the ground stake or changing antenna patterns between Peak and Null.
The higher-priced locators come with an increased ability to solve a range of underground wiring problems – longer wire tracking distance, multiple ways of connecting to cables, and better ability to spot wiring faults.
Lower priced locators are equipped to do simpler tasks like tracking wires and finding valves, sometimes over shorter distances.