Air Monitor VELTRON DPT 2500-plus, Инструкция по установке, эксплуатации и обслуживанию

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VELTRON DPT 2500-
plus
Air Monitor Corporation
116-047-20.PMD (5/5/11)
VELTRON DPT 2500- plus
- IO&M Manual
3
SECTION 3 – FEATURES
3 – FEATURES
3.1 – USER SETUP MENU
The microprocessor program cont a ins a User Setup menu system for setting user selectable p a rameters. Four
pushbuttons, allow the user access to the menu for setting configuration modes and values. Refer
to the Configuration Programming (Section 5.6) instructions for operation det a ils. Also contained in the User Setup
menu is all input and output calibration. T he calibration method is completely digital and cont a ins no analog
potentiometer adjustment s which are susceptible to drif t. Non-volatile memory is used for storing all setup p ar ameters
and calibration values, and will remain unchanged af t er set, even when power to the unit is of f .
3.2 – TRANSMITTER HOLD
Certain operations performed by the microprocessor place the unit into a
Ho ld
mode. This occurs when the User
Setup menu system is activated or when an A UTO-zero is performed. When in
Hold
, all
Normal
mode processing is
halted and the output is held at its last value prior to Hold . Normal operation is indicated by the "CPU Activated" 
(dot) in the lower le f t of the display blinking at a rate of four times per second. A Hold mode is indicated by the "CPU
Activated"  (dot) blinking at a rate of once per second.
3.3 – AUTOMATIC ZEROING
At periodic intervals the microprocessor will automatically execute an AUTO-zero cycle consisting of the following
sequence: The transmitter output and display signals are put on Hold ; a valve is activated which disconnect s the
process high pressure from the high port of the transducer and connect s the process static pressure to both sides of
the transducer, creating a true zero differential pressure; after a brief st a bilization period, the transducer zero offset
signal is measured and stored in memory; the valve is deactivated and af ter a brief period for process signal st ab ilization,
the Hold is released and Normal process measurement resumes. will be displayed whenever AUTO -
zero cycle is in progress.
During Normal operation, the zero of fs et value stored in memory is subtracted from subsequent transducer readings
until the next A UTO-zero cycle occurs and repeat s the process. For calibration purposes a switch is provided which
allows the user to manually activate the zeroing valve . AUTO-zero On/Off and Interval are available and configurable
using the User Setup menu.
3.4 – DATA DISPLAY
The large integral display is a backlit graphical LCD that displays the current measured process, and is used during
configuration.
3.5 – HIGH TURNDOWN RATIO OPERATION
The VELTRON DPT 2500- plus transmitter, with it s high level of accuracy and automatic zeroing circuitry , c an maintain
linear output signals on applications requiring velocity turndown of 10 to 1 (equal to a velocity pressure turndown of
100 to 1).
3.6 – ENCLOSURE
The VELTRON DPT 2500-
plus
transmitter is packaged in a NEMA Ty pe 1 enclosure with standard industrial process
connections. A NEMA Type 12 enclosure is optionally available.
3.7 – MULTIPLE OPERATING POWER SELECTIONS
The VELTRON DPT 2500- plus can be powered by 24VAC or 24VDC.
auto zero
X