Instruction manual

Micro Motion
®
Model D and DT Sensors Instruction Manual 45
Troubleshooting continued
Inaccurate density reading
Symptom
The flowmeter density measurement is erratic, or is lower or higher than
the density of the fluid.
Troubleshooting instructions
To troubleshoot an inaccurate density reading, you will need one of the
communications devices listed on page 46 or a transmitter with a
display. Refer to the table below for the necessary steps to troubleshoot
an inaccurate density reading.
Table 4. Troubleshooting inaccurate density reading
Procedure Instructions What to do next
1. Check for stable density reading
at the transmitter
See page 50 • If the density reading is stable, go to step 2
• If the density reading is not stable, go to step 3
2. Check for the proper density
calibration factor
See page 49 • If the dens cal factor is correct, go to step 4
• If the dens cal factor is incorrect, change it, then go to
step 11
3. Check for faulty or improperly
installed flowmeter wiring
See page 47 • If the flowmeter wiring is OK, go to step 4
• If the flowmeter wiring is incorrect or faulty, fix or replace it,
then go to step 11
4. Check for faulty or improperly
installed grounding
See page 51 • If the grounding is OK, go to step 5
• If the grounding is incorrect or faulty, fix it, then go to step 11
5. Check to see if the density reading
is low or high
See page 50 • If the density reading is low, go to step 6
• If the density reading is high, go to step 10
6. Run a quality check on the
process fluid
Use your plant
procedures
• If the product quality is OK, go to step 7
• If the product quality is not OK, fix it, then go to step 11
7. If you checked the wiring in step 3,
go to step 8, otherwise, check for
faulty or improperly installed
flowmeter wiring
See page 47 • If the flowmeter wiring is OK, go to step 8
• If the flowmeter wiring is incorrect or faulty, fix or replace it,
then go to step 11
8. Check for two-phase flow See page 53 • If there is no two-phase flow, go to step 9
• If there is two-phase flow, fix the problem, then go to step 11
9. Check for vibration or crosstalk See page 53 • If there is no vibration or crosstalk, go to step 12
• If there is vibration or crosstalk, eliminate it, then go to
step 11
10. Check for plugging or build-up on
the sensor flow tubes
See page 54 • If the tubes are not plugged, go to step 12
• If there is plugging or build-up, clear the tubes, then go to
step 11
11. Check again for inaccurate density
reading at the transmitter
See page 50 • If the reading is correct, you’ve solved the problem
• If the reading is still wrong, start over at step 1 or go to
step 12
12. Contact Micro Motion Phone numbers are
listed on page 41