Air Monitor VELTRON II, Installation, Operation And Maintenance Manual

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VELTRON II
Air Monitor Corporation
116-011-98.P65 (8/30/10)
VELTRON II - IO&M Manual
3 – FEATURES
3.1 – OPERATOR SETUP MENU
The microprocessor program contains a Operator Setup menu system for setting user selectable parameters. Four
pushbuttons,
ESC, UP, DN, ENT allow the user access to the menu for setting configuration modes and values. Refer
to the Configuration Programming (Section 5.6) instructions for operation details. Also contained in the Operator Setup
menu is all input and output calibration. The calibration method is completely digital and contains no analog potentiometer
adjustments which are susceptible to drift. Non-volatile memory is used for storing all setup parameters and calibration
values, and will remain unchanged after set, even when power to the unit is off.
3.2 – TRANSMITTER HOLD
Certain operations performed by the microprocessor place the unit into a Hold mode. This occurs when the Operator
Setup menu system is activated, when an AUTO-zero is performed, or when an AUTO-purge cycle is in progress.
When in
Hold , all Normal mode processing is halted and outputs are held at their last value prior to Hold . Normal
operation is indicated by the "CPU Active" LED flashing at a rate of four times per second. A Hold mode is indicated by
the "CPU Active" LED flashing at a rate of one time 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 disconnects the
process high pressure from the high port of the transducer and connects the process static pressure to both sides of
the transducer, creating a true zero differential pressure; after a brief stabilization period, the transducer zero offset
signal is measured and stored in memory; the valve is deactivated and after a brief period for process signal stabilization,
the
Hold is released and Normal process measurement resumes. During Normal operation, the zero offset value stored
in memory is subtracted from subsequent transducer readings until the next AUTO-zero cycle occurs and repeats the
process. AUTO-zero On/Off and Interval are available and configurable using the Operator Setup menu.
3.4 – AUTO-purge MANAGEMENT (option)
For "dirty process air" applications requiring the use of an Air Monitor AUTO-purge system, the VELTRON II provides the
capabilities of establishing purge frequency and duration, while also giving the user a choice of either internally timed
cycle frequency or externally triggered purge initiation. During the purge cycle all transmitter outputs are maintained at
their last value prior to the start of the purge cycle.
3
SECTION 3 – FEATURES