Peak response is the most accurate of locating modes as it uses both horizontal antennas. You get a “Peak” signal response over the centre of the radiated signal from the buried line.
BROAD PEAK RESPONSE
Broad Peak response only uses a single horizontal antenna, but, is extremely useful if a buried line is particularly deep. Such as approaching a river crossing.
Null uses the vertical antennas and provides a minimum or “Null” response over the centre of the radiated signal. Some users prefer the null response, but, it can be affected by distortion. However, the left/right arrows can assist with direction to move the receiver to locate the position of the buried service.
PEAK WITH ARROWS RESPONSE
Peak with arrows response works the same way as Peak above in regards to the bar graph response. However, the arrows use the null antenna and can be affected in distorted fields. The arrows are very handy for training a new operator in guiding them back to field on the service. If the arrows appear to indicate a different position of the service to the peak response then this is a good indicator of a distorted field.