Alnor HM680, Owner'S Manual, Page: 13 / 40

Chapter 3. Getting Started 7
6.
Reinstall the battery holder. Ensure the battery holder orientation is such that its terminals make
contact with the spring contacts within the battery compartment.
7.
Replace the battery compartment cover.
Notes
: The NiMH batteries included with the instrument may require recharging prior to first use.
Fully charged batteries should enable the instrument to operate for a period of at least twelve
(12) hours
Setting the battery-type selection switch properly will prevent unwanted charging of non-
rechargeable alkaline batteries and provide charging of NiMH batteries when the AC adapter is
connected.
A battery charge life remaining indicator is shown on the display whenever the manometer is
powered by batteries, and turned on.
When using NiMH batteries, the indicator of battery charge life remaining will not be accurate
due to their inherent non-linear voltage drop with power use.
Due to the danger of battery leakage, remove batteries from the battery compartment prior to
storage.
Never
mix battery types.
For maximum battery life, ensure backlight is “off” when not needed.
Instrument Start-up
Upon turning the HM680 Hydronic Manometer on, the meter will engage in a brief self-check while
displaying the serial number, model number, and revision of the instrument being used. In completing the
self-check, the user is given the option to zero the gauge pressure sensor prior to proceeding to the
Pressure Measurement Screen.
Zeroing the Manometer
The HM680 Hydronic Manometer is equipped with both a gauge and differential pressure sensor,
allowing for simultaneous measurement and display of High-side gauge and Differential pressure. The
gauge and differential pressure sensors are zeroed independently of one another.
Zeroing the Gauge Pressure Sensor
To ensure the most accurate gauge pressure ( High P ) measurements, the HM680 gauge pressure sensor
should be zeroed prior to taking readings on each new system. When not in the instrument start-up
sequence, the gauge pressure sensor is zeroed as follows:
1.
Enter the Main Menu.
2.
Select Zero Gauge Pressure .
3.
Follow the on-screen instruction to complete the gauge pressure sensor zeroing process.
Notes
: Zeroing the gauge pressure sensor requires the user to disconnect the High pressure (red)
hose; as such it is often most convenient to zero the gauge pressure sensor as part of the
start-up sequence (i.e,. before hoses have been connected).