Specifications

Multi-Zone Gas Monitors
P/N: 3015-5074 Rev 10 45
4.9.2. Diagnostic Screen Overview
The Diagnostic Screen contains sensor data and status information useful for trouble shooting various fault
conditions. An explanation of the information provided on each line of this screen is listed below, including
normal operating ranges.
Field Name Description
xxxx FEET
Programmed length of tubing for an active zone.
xx ZONE name
Current active zone and user-programmed name. This field may also show “WARM UP”
during warm up mode.
DET
Detector Voltage – Peak-to-peak output of the IR sensor. In the absence of gas, this value
range is 4.100V to 4.300V.
AVE Average Detector Voltage – Running average of the values displayed in line 1.
ZERO
Zero Voltage – IR sensor output that was stored during the last purge cycle and has the same
range as line 1.
NOISE
A 16 point running average of the noise portion of IR bench output. This reading is valuable
mostly when gas is not present.
AVEAU
Average Absorbency – Optical absorbency computed from the Average Detector Voltage and
Zero Voltage. In the absence of selected gas, the absorbency is 0.000AU. When sampling
desired gas, its value varies proportionally with the gas concentration.
UM/L
uMoles/L – Absolute concentration in micro-moles per liter of gas based on Noise and the
internal calibration. There are two figures displayed. The first (annotated by a B) is the actual
measurement at the IR bench. The second is the calculated value corrected to ambient
conditions (temperature + pressure).
PPM
Parts Per Million is the volume concentration referenced to standard temperature and
pressure and is computed from the Average Absorbency, Zero Temperature and Ambient
Pressure. There are two figures displayed. The first (annotated by a B) is the actual PPM at
the IR bench. The second is a PPM reading normalized to standard temperature and
pressure.
ZERO
Zero Temperature – Displays the sensor and enclosure temperature measured and stored
during the last purge cycle in degrees C.
BENCH
Bench Temperature – Current IR sensor temperature in degrees C as well as the raw voltage
coming from the temperature sensor. This value can range from ambient to ambient +15
degrees C.
BOX
Box Temperature – This is the current internal enclosure temperature along with the raw
voltage from the temperature sensor, and has the same range as the Bench temperature.
PRES
Pressure – This is the current absolute manifold pressure in PSIA along with the output
voltage of the pressure sensor. This value should always be 0.2 to 1.0 PSIA below ambient
(AMB).
VAC
Vacuum – The vacuum pressure is measured every purge cycle by closing all sample valves.
Its value is typically 2.5 to 4.0 PSIA below ambient pressure.
AMB
Ambient – Ambient pressure is measured every purge cycle with the sample pump off and the
manifold open. Its value is weather and altitude dependent and can range from 10.0 to
15.5 PSIA.
FAULT Fault code listed in hexadecimal. See Fault Code list.
y.yyyX
Calibration multiplier used when measuring concentration.
TCx.xxxx
Temperature Compensation – magnitude of voltage applied to sensor output (in volts).
Factory use only.
MODBUS data
485 RX=x Receive port number of bytes FUNC Function
485 TX=x Transmit port number of bytes REG=xxxxx Register address