Hardy HI 2151/30WC Single-Scale Controller - Manual (Page 133)

Chapter 8 - Troubleshooting
8-13
B1 - Guidelines for Instabilities on Formerly Operating Systems (Cont'd)
Mechanical Stability
Vessel -
When inspecting a vessel keep in mind, the Center of Gravity (COG) should be
low and centered equally over all the load cells.
Insure the load is directly over or under the load point to avoid side-loading.
Insure there isn't any side loading from piping or external forces.
Install flexures on all piping to insure a free floating vessel.
Insure the vessel and loadcell mounts are mechanically stable and fixed.
Large changes in individual Loadcells indicate a shift in COG or faulty
Loadcells.
Piping and motors will effect the individual loadcell readings.
Allow for a higher reading on Loadcells that support motors and piping.
Insure pneumatic lines are not applying pressure to the vessel when energized.
Use check (stay) rods to minimize vessel movement.
Insure the check rods are loose and not interacting with the vessel.
Power down all vibration, vacuum and pressurization equipment during the test
process.
B2
Configuration settings
Incorrect Waversaver settings can cause unstable weight readings
Adjust to the lowest WS setting that gives you a stable reading.
Higher frequencies with low amplitude vibrations; - Use WS settings 1 or 2
Low frequency with high amplitude vibrations; - Use WS setting 3 and higher.
Incorrect number of decimal places; Reading weight increments beyond the
equipments applications level. (see guideline caluculations below)
Repeatability -
Divide the total loadcell capacity, including decimal points, by 10,000.
(expected stable weight reading).
Resolution -
Divide the total loadcell capacity, including decimal points, by 30,000.
(The amount you can expect to see, but not necessarily stable)
B3
Stable ? No
Stable ? No
Yes
Yes
Return To
A
I.T. Diagnostics
C