The OFS-2000W model is equipped with Automatic Gain Control (AGC) to compensate for variations in opacity caused by particulate matter or moisture carried in the flow.
OSi's patented Optical Flow Sensor (OFS) makes drift-free measurements across the entire stack, duct or pipe diameter and calculatesMore a true average flow reading. The OFS 2000-W model is equipped with Automatic Gain Control (AGC) to compensate for variations in opacity caused by particulate matter or moisture carried in the stack flow. The OFS uses our EPA Method 14 approved optical scintillation technology. The optical scintillation technique relies on advanced Digital Signal Processing (DSP) electronics to "see" and measure the movement of turbulence found in a gaseous flow stream to provide highly accurate, path-averaged air velocity measurements. The accuracy of the OFS has been proven both in the NIST wind tunnel, and time after time in real-world applications.
The OFS consists of DSP/multiprocessor - based control unit teamed with a set of optical transmit and receive heads which are easily installed on opposite sides of a stack, duct, vent or pipe. The OFS heads mount fully outside of the media volume behind optical windows for easy access, more accurate measurements, and greater durability. The transmit head sends a visible diverging light beam (easy to align and vibration resistant) directly across and perpendicular to the flow (although existing angled-path port can be used). The control unit processes the fluctuations seen by the receive head and displays the flow data locally and transmits it to a PC, PLC, DAS or other data collection device that accepts a serial data link and/or a 4-20 mA current loop. The control unit can be configured from either the local keypad and display, or from a laptop or portable terminal. Less
OSi's patented Optical Flow Sensor (OFS) makes drift-free measurements across the entire stack, duct or pipe diameter and calculatesMore a true average flow reading. The OFS 2000-W model is equipped with Automatic Gain Control (AGC) to compensate for variations in opacity caused by particulate matter or moisture carried in the stack flow. The OFS uses our EPA Method 14 approved optical scintillation technology. The optical scintillation technique relies on advanced Digital Signal Processing (DSP) electronics to "see" and measure the movement of turbulence found in a gaseous flow stream to provide highly accurate, path-averaged air velocity measurements. The accuracy of the OFS has been proven both in the NIST wind tunnel, and time after time in real-world applications.
The OFS consists of DSP/multiprocessor - based control unit teamed with a set of optical transmit and receive heads which are easily installed on opposite sides of a stack, duct, vent or pipe. The OFS heads mount fully outside of the media volume behind optical windows for easy access, more accurate measurements, and greater durability. The transmit head sends a visible diverging light beam (easy to align and vibration resistant) directly across and perpendicular to the flow (although existing angled-path port can be used). The control unit processes the fluctuations seen by the receive head and displays the flow data locally and transmits it to a PC, PLC, DAS or other data collection device that accepts a serial data link and/or a 4-20 mA current loop. The control unit can be configured from either the local keypad and display, or from a laptop or portable terminal. Less
Unit of Measure
Advantages
|
Options
|
Accessories
|
Flow Performance
|
Media/Environmental
|
Physical Specifications
|
Electrical Specifications
Advantages
Advantages |
N/A
|
Options
Options |
N/A
|
Accessories
Accessories |
N/A
|
Flow Performance
Measurement Technique |
N/A Optical Scintillation (OSi Patented) |
Dynamic Range |
N/A 0.1 to 40 m/sec |
Accuracy (Absolute) |
N/A ±0.1 m/sec basic -or- ±2% of reading, whichever is greater |
Repeatability (Relative) |
N/A ± 0.1 m/sec basic -or- ±1% of reading, whichever is greater |
Long Term Drift |
N/A Less than 1% per year |
Response Time |
N/A 3 to 600 seconds, user selectable |
Automatic Calibration |
N/A 2 or 3 point; user selectable interval -or- on external command |
Sensor Health Monitoring |
N/A Continuous self-test of voltages, performance, optics, etc. |
Media/Environmental
| Stack/Duct/Pipe Diameter (Standard)1 | N/A 0.2 to 12 m |
Media Temperature/Pressure/Humidity |
N/A No effect on measurement |
Media Transparency |
N/A Up to 95% opacity (OFS-2000-W is recommended for high opacity) |
Ambient Temperature |
N/A -50 to 60 ºC-58 to 140 ºF |
Condensing Humidity |
N/A 0 to 100 % |
Physical Specifications
Light Source |
N/A Eye-safe 670 nm visible red LED, 5 deg. divergence angle |
Sensor Head |
N/A 9 x 9 x 13 in |
Sensor Head Weight |
N/A 13 lb |
Note for Sensor Head |
N/A
With 4 in. scheduled 40 flange extender. NEMA4 weather resistant. |
Control Unit Dimensions: Rack Mount Version (Standard) |
N/A 5 x 17 x 20 in |
Control Unit Weight: Rack Mount Version (Standard) |
N/A 13 lb |
Note for Control Unit: Rack Mount Version (Standard) |
N/A For indoor use. |
Control Unit Dimensions: NEMA4 Wall Mount (Optional) |
N/A 12 x 16 x 10 in |
Control Unit Weight: NEMA4 Wall Mount (Optional) |
N/A 15 lb |
Note for Control Unit: NEMA4 Wall Mount (Optional) |
N/A For outdoor/factory floor use. |
Purge Air for Heads |
N/A Normally not needed. 1-2 CFM max for some very dirty applications |
Electrical Specifications
User Interface |
N/A RS-232 serial I/O and / or 4-20 mA optically isolated current loop; Also two sets of relay contacts for fault and calibration indication. |
Power for Transmit Head |
N/A Universal 100-240 VAC, 50/60 Hz, 12 VA (fused & surge protection) |
Power for Control Unit |
N/A Universal 100-240 VAC, 50/60 Hz, 40 VA (fused & surge protection) |
Cable between Control Unit and Receive Head |
N/A 15 foot standard; to 300 foot optional (shielded, 10 cond., 22 AWG) |
- 1 Consult factory for other ranges.
