Alnor HM680, Owner'S Manual, Page: 33 / 40

Chapter 7. Maintenance and Troubleshooting 27
Never
mix battery types.
NiMH batteries should only be charged at room temperature. Starting with batteries that are
too cold or too warm can cause the charge cycle to terminate early.
Calibration
TSI recommends that the HM680 Hydronic Manometer receive an annual calibration. TSI will verify
calibration of the instrument and re-issue a certificate of calibration with traceability to NIST. This
“annual checkup” helps to ensure the specified accuracy of the instrument is maintained.
To calibrate the instrument, please ship TSI the complete package that includes the meter and accessory
temperature probe. Everything should be packed carefully within the carrying case and then inside a
shipping box. The original shipping box is preferred. Prior to shipment, please contact Customer Service
for an RMA (Return Materials Authorization) number at (651) 490-2707, (800) 861-7897; or visit the
service page on our website at
www.alnor.com to complete an RMA# form online.
Ship directly to: TSI Incorporated
ATTN: Customer Service
500 Cardigan Road
Shoreview, MN 55126-3996
Troubleshooting
The following table lists the symptoms, possible causes, and recommended solutions for common
problems encountered with the instrument. If your symptom is not listed, or if the recommended solutions
do not address your problem, please contact the factory.
Symptom Possible Causes Corrective Action
No display Unit not turned on.
Low or dead batteries.
Dirty battery contacts.
AC adapter not connected. Press On/OFF key.
Replace or recharge the batteries.
Clean the battery contacts.
Plug in AC adapter.
“ “
flashing on display
Low battery charge.
Dirty battery contacts. Replace or recharge the batteries.
Clean the battery contacts.
“8888”
flashing on display The indicated measurement is
out of range. The allowable ranges for pressure and
temperature measurements are shown on
the specifications page.
“-----”
on display The indicated value is invalid. The allowable ranges for pressure and
temperature measurements are shown on
the specifications page.