CAMM
Air Monitor Corporation
116-044-91.P65 (8/31/10)
CAMM - IO&M Manual
3 – FEATURES
3.1 – OPERATOR SETUP MENU
The CAMM microprocessor program contains a Operator Setup menu system for setting Operator selectable
parameters. Four pushbuttons,
ESC, UP, DN, ENT
allow the Operator 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 – AIR DENSITY CORRECTION
The CAMM is capable of performing both process temperature and process static pressure correction. Temperature
input is an analog signal from a remote temperature transmitter; non-linear temperature inputs can be linearized by
the microprocessor. Process static pressure is measured by means of an internal absolute pressure transmitter
connected to the transmitter static pressure signal input.
3.3 – 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 and displays are held at their last value prior to
Hold
.
3.4 – 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.
3.5 – AUTO-purge MANAGEMENT
The CAMM provides the capabilities of establishing purge frequency and duration, while also giving the Operator a
choice of either internally timed cycle frequency or externally triggered purge initiation. During the purge cycle all
transmitter outputs and displays are maintained at their last value prior to the start of the purge cycle.
3
SECTION 3 – FEATURES
Summary of Contents for CAMM
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