Honeywell NK User Manual page 35

5. If an overrange indication is still present, the problem may be with the
Model NK. Contact our Service Department.
5.2.3 Erratic readings
Erratic readings could indicate that the batteries are weak.
1. Check the batteries for low voltage or mismatched polarities. Replace
weak batteries.
2. If the batteries are strong and installed properly but erratic readings are
still present, contact our Service Department.
Maintenance and Repair 31