Hoffer Flow Controls HRT1, User Manual

Page: 31 / 67

Operation and Maintenance 23
HRT1 HP-313
5. OPERATION AND MAINTENANCE
5.1 Display Parameters
The HRT1 calculates and displays total volume and flow rate on a
two-line liquid crystal display (LCD). The top line is an 8-digit Total
Volume display and the bottom is a 5-digit Rate display. The 8-digit
non-resettable Grand Total is also viewed on the top line by
pressing
The Grand Total will be displayed for approximately 15 seconds before
returning to the Total Volume display.
Volume units and the time base for flow rate are indicated by icons on
the
right hand side of the LCD. When no icon for time units is
displayed, the time base is /SEC.
A Bar graph located at the bottom of the LCD provides a graphical
representation of the flow rate based on a percentage of the maximum
flow setting.
The flow rate and flow total are calculated and updated on the display
once every 2 seconds.
5.2 Saving Grand Total
To minimize the number of write cycles to non-volatile memory, the
Grand Total is saved once per minute. In the event that both loop
power and battery power are removed simultaneously, the Total will be
lost and the Grand Total could be up to one minute old when restoring
power. When changing the battery (see
Section 7 Maintenance ), it is
recommended to stop the flow at least two minutes prior to removing
power from the unit to ensure that the stored Grand Total is current
when restoring power.
5.3 Clearing the Total
The Volume Total may be cleared by using a magnet, a contact closure
to power common on the RESET input terminal, from the front panel
keypad or via HART communications (See Chapter 6 HART
Communications).