Technical Manual
Page 2
CODEL
OPS.109
Issue : B
Rev. : 1
Date : 23/10/13
Doc. i/d : 0109/6
Ref. : 090028
1.2. Transducer Units
Each transducer unit consists of a broad band infrared detector, a lens to focus the radiation received on the
detector and a pre-amplification circuit board, all housed within a fully sealed, epoxy-coated aluminium
enclosure. The transducers are supplied with air purge units to maintain the cleanliness of the transducer
windows.
1.3. Power Supply Unit (PSU)
The PSU accepts mains input voltages and provides the 48V DC supply for the transducers.
1.4. Signal Processor Unit (SPU
The V-CEM5100 signal processor receives its 48V DC power from the Power Supply Unit (PSU). Signals from
the two transducers are processed and correlated to derive the transmission time of the gas flow from the first
transducer to the second and thus compute the gas velocity. Diagnostic communication is provided via the Data
Display Unit (DDU).
Gain adjustments for the transducer detector signals are provided by trim potentiometers in this processor.
Details for adjustment can be found in Section 6.6. Detector Levels.
1.5. Data Display Unit (DDU)
A remote DDU is connected to the SPU via a 4-core data bus up to 1km in length. The DDU enables all output
and diagnostic data to be accessed on a 2-line, 32-character, alpha-numeric display and keypad. It also
provides 2 x 4-20mA outputs and 2 x volt-free contact relays for alarms. These outputs are fully configurable
from the keypad and display.