Flow & Opacity Monitors

Optical Scientific OFS-2000
Real-Time Optical Flow Monitor


The OFS-2000 Real-Time Optical Flow Sensor is easier, more accurate, and cost-effective than current sensors to measure flow. The OFS-2000 uses EPA - approved technology. The system consists of a control panel with optical transmitter and optical receiver which are easily installed on opposite sides of a smokestack, duct, vent, or other confined space. The OFS-2000 resides outside the stack chamber behind optical windows, for easy access, more accurate measurements, and greater durability. The instruments are mounted on the same level to transmit the LED beam directly perpendicular to the flow. The optical scintillation technique measures the movement of the turbulence found in exhaust flow streams to provide highly accurate, path-averaged air velocity measurements. Using fast and highly efficient Digital Signal Processing (DSP), the control unit processes the data and transmits it to a PC, PLC, DAS or other data collection device that accepts 4-20 mA or digital input. The OFS-2000 self-testing and diagnostics software monitors performance to alert the user to any maintenance issues. In addition the OFS can be easily installed; facilitating it's use if your existing flow sensor fails. (Existing angled flanges can be used)

• Revolutionary Non-Intrusive Setup Greatly Reduces Maintenance
The OFS is a patented, advanced, continuous flow measurement system for large and small stacks or ducts. The instrument is isolated from the flue gas. This non-contacting method ensures reduced maintenance over traditional flow sensors.

• True Cross-Stack Path Averaging Exceptionally Accurate - Long Term Drift Less Than +/-1%
Provides the true average velocity across the diameter between the optical sensors beam path. The accuracy of the OFS is traced back to the NIST wind tunnel standard. Long term drift of the system is less than +/- 1% over the entire life of the instrument.

• Calibration and Other Checks Verify All System Components
OFS meets all EPA Part 40 CFR 75 requirements, including daily calibration zero and span checks. System components and interference checks are completed on a continuous basis.

• Velocity Measurement Independent of Temperature, Pressure, and Density of Flue Gas
OFS measures the flu gas velocity. Path angel and gas composition, whether wet or dry, hot or cold, has no adverse effect on the measurement of velocity. OFS has CE, CSA, and UL marks. Optical Scientific, Inc. is ISO-9001 certified.

FLOW PERFORMANCE
Technique Optical scintillation
Range 0.1 to 40 m/s velocity
Accuracy 2% of reading
Resolution 0.1 m/s
Response Time User selectable 3 sec to 600 sec
Long Term Drift <1% >6 months
Media Temperature No limit
Stack/Duct Diameter 1 – 10 m standard, other ranges available
Light Source 670 nm red LED
Beam Divergence 5 degrees
Optics Quartz
Purge Passive purge. Factory-supplied purged air with 1-2 CFM (optional)

MAINTENANCE
Calibration Automatic 2- or 3-point calibration once per day or as requested by External Calibration Request
Diagnostics Continuous monitoring of sensor status including power supply voltage check, performance check, optics
contamination, etc
Indicators TX and RX Optical Units - LED's indicating power ON & correct operation
Control Box - LED's indicating correct operation

OPERATIONAL ENVIRONMENT
Ambient Temperature -40 to 60 C
Dust Intrusion IP65
Moisture 0-100% condensing if dry purge air supplied
DATA OUTPUT
4-20 ma optical isolated output with auxiliary current loop (optional)
Two relays for fault and calibration indications
RS-232 ASCII, fixed data string - 2 types Short with only velocity and P/F status
Long with all velocity and status data
Optional Limited Distance Modem (LDM)
Optional Fiber Optic Modem (FOM)
User Selectable with Integral Key Pad & Display including Sensor ID
Baud rate (9600 standard)
Averaging Time
Units of Measure

MATERIALS
TX & RX Optical Units Aluminum with powder-coat paint
Control Box Aluminum with powder-coat paint (NEMA-4)
Steel and Aluminum (rack mount)
Extender Aluminum with powder-coat paint

PHYSICAL CHARACTERISTICS
Weight TX & RX Optical Units 5 kg ea
Control Box 7 kg (nema-4), 6 kg (rack mount)
Extender 3 kg ea
Dimensions TX & RX Optical Units 15 x 15 x 14 cm ea
Control Box 30 x 40 x 25 cm (nema-4), 13x43x51 cm (rack)
Extender standard 4" pipe flange (9-inch diameter) X 6-inch (15 cm long)

POWER REQUIREMENTS FUSE, SURGE, & EMI PROTECTED
Transmitter Unit Universal 100-240 VAC, 50/60 Hz, 12 VA
Control Box Universal 100-240 VAC, 50/60 Hz, 40 VA


EMS Model 1304 Opacity Monitor

The EMS 1304 Opacity Monitor is designed with state of the art modular packaging with serviceability in mind. A built-in TTL (through-the-lens) alignment system allows the alignment target to be viewed through a window on the transceiver. Adjustments to changes in alignment are provided by a 3 point alignment system which is integral to the air plenum. This insures optimum reliability while enabling the system to be easily serviced and maintained in the field by plant service personnel.

Key Features

• Digital display with selectable Instant opacity, average % opacity and time to next cal
• EPA required zero and span check can be performed automatically by internal clock, external initiation or manually on demand
• Standard EPA required Audit Test Kit
• Two large bar graph displays; one for instant opacity and one for average opacity
• Separate bar graph display for window dust
• Communications via MODBUS (RS-485)
• Sensor located service module with a digital display % correlated opacity, %T2, manual zero and span
• Standard 3-30 foot retro (longer distances available)
• Stack exit correlation
• Light source rated for 7 years

Remote Control Unit
Numeric Digital Display: 5/8 inch (15.9 mm), 4-digit LED
Selectable for Instantaneous opacity, Average Opacity. Optional mg/m3
Opacity range and resolution: -5 to 100% opacity, 0.1% Opacity (mg/m3 optional)
Alphanumeric 8 character LED (0.2") Fault Display:
Air purge low, No Stack Power, T2 4-20 Lost/low, Maintenance Mode, Window Dust, Zero Cal Fail, Span Cal Fail, Manual Cal.
Bargraph Left/Right: 51 segments LED (5.1") for instant/average opacity. 20 segment LED (2.1") for window dust and drift in %opacity
Operator Indicating LED’s: Run, Alarm, Operate, Cal in progress
High Opacity Set Point: 0-100% of full scale
High Opacity Delay: Adjustable 0-300 Seconds
Hi Opacity Alarm Reset: Automatic
Open Transistor Collector Outputs: Four selectable
Dry Contacts: Two selectable (option: two additional)
Instantaneous Opacity and Average Outputs: 4-20 mA grounded reference, 800 ohms max. (two additional optional)
Note: at -5% opacity outputs go to 3.2mA. to meet ASTM and PS-1 specifications.
OPLR (Exit Correlation Lx / 2*Lt): 0.3 to 3.0
Cal cycle initiate: Local, remote and timed Adjustable 1 to 24 hours
Enclosure: NEMA 13, Height: 7.38" x Wide: 3.00: x Depth: 7.75", Weight: 6 lbs.
Ambient Temperature Range: +0o to +50 o C ( +32 o to + 122 o F)
Power Requirements: 120 VAC (+/- 10%), 50/60 Hz, 22VA
Network: Protocol: Modbus (ASCII or RTU mode), type RS-485, optically isolated, RS-232 with telephone modular handset connector.
Configuration Speed: 1200-38,400 baud, type RS-232 and RS-485

Transceiver Service Module
Power: 120/240vac +/-10% 65va, 60va
Display: 5/8 inch (15.9 mm), 4-digit LED, selectable for % Opacity and % Transmittance
Local zero/span: Manual on demand
Test jacks: Transceiver to remote control current loop
Diagnostics: Loss of power, Current loop open, maintenance mode.

Transceiver/Reflector
Enclosure: NEMA 4 watertight enclosure.
Path Length: 2 to 15 feet, 0.6 to 4.6 meters. Longer available
Optical System: Double Pass
Light Source Aging Compensation: Automatic
Light Source Life: > 6 years, Field replaceable without removal of the transceiver from the stack.
Ambient Temperature Limits:-4 o to +130 o F (-20 o to +54 o C) (Cold weather option available.)
Alignment Verification: Passive Built-in through-the-lens system:
Mounting Flanges: 3 inch IPS, 150# pipe flange
Ambient Light Immunity: Per ASTM D6216 <2% opacity, Solid-state electronic light modulation

EMS Model 1304 Opacity Monitor (EPA PS-1 Compliant*)
*This item may require inhouse and/or on-site installation and training.

Download an Opacity Data Form to submit project details.
Or call us at 800.399.4236 or email a Sales Engineer.