Insert the new batteries after processing the reset operation which can completely discharge the condenser for the HT series Handheld Digital Tachometer.

Operating procedure

 

1. Remove the batteries.
2. Press and hold the measurement switch (button) for few seconds.
3. Insert the new batteries.

 

Please replace all the batteries at the same time. If you mix new and old ones, the lifetime of the batteries will be shorter due to their potential difference.