| Number | Fault phenomenon | Reason for malfunction | Handling measures | Notes |
| 1 | The elliptical gear is not turning. | A foreign object has jammed the gears. | Clean and inspect instruments and pipelines, wash or replace filters. | |
| 2 | Axial seal coupling leakage | Seal packing wear or lack of sealing oil | Tighten the gland or replace the packing, and add sealing oil | |
| 3 | The pointer rotates unstably | The pointer washer is loose or the rotating parts are not flexible | Re tighten to eliminate inflexibility | |
| 4 | Excessive negative
measurement error |
Bearing wear or deformation or measuring chamber | replace bearings, repair measuring chamber and gears | After repairs,calibration is required. |
| 5 | Significant changes in measurement errors | Oil contains gas | Install gas separator | |
| 6 | Pointers and counters cannot reset to zero | The internal gear of the meter head is damaged or the knob of the meter head is damaged due to collision | Replace the zero return handle,adjust the internal gear or replace the header with a new one |
