THE Optical Flow Sensor (OFS) is a continuous flow measurement system for small and large stacks and ducts.
OFS meets all 40 CFR 75 requirements, including daily zero and span checks and is available as a rack mount or NEMA-4X unit.
Available from Thomson Environmental Systems , the sensor consists of a control panel teamed with an optical transmitter and optical receiver.
The transmitter and receiver are installed in-line with each other on opposite sides of the smokestack, duct or vent. There is no need for 45° angle mounting.
An LED beam from the receiver is directed straight across the stack, perpendicular to the flow, providing an accurate check across the stack flow or velocity measurement. Long term drift for the system is less than ±1%.
The OFS resides outside the stack chamber, behind optical windows. This provides added protection, reduced maintenance and easy access to the OFS components.
The OFS uses optical scintillation technology. The OFS measures the movement of turbulence found in the sample stream or exhaust.
This method ensures measurements are not effected by gas composition or temperature. The control panel processes the data and transmits to data collections devices via 4-20mA or digital signal.
The OFS comes fully equipped with self-testing and diagnostic features to monitor its own performance and alert the user if maintenance is required.
Instrument malfunction and limit alarms are available from the control panel.