When I switch on my locator, it displays 'err 150' on the screen.

This error is normally associated with the 'real time clock circuit' in the locator.  All data logging locators contain an on board battery that powers this circuitry when the locator is switched off so that the date and time clock continue to operate correctly, even when the unit is switched off.  In general this battery should last between 3 and 5 years, dependent upon usage and environmental conditions etc.

If the real time battery falls below specific levels, the locator will detect this and display the 'err 150' message on power up.  The locator performance or operation will not be compromised but time and date information on the stored data logs will be incorrect.

Please note, the real time battery can only be changed by Radiodetection service or an authorized Radiodetection service center.