Model 205 Dual Beam Ozone Monitor™
EPA Federal Equivalent Method (FEM)
The Model 205 Dual Beam Ozone Monitor makes use of two detection cells to improve precision, baseline stability, and response time. In the Dual Beam instrument, UV light intensity measurements Io (ozone-scrubbed air) and I (unscrubbed air) are made simultaneously. Combined with other improvements, this made it possible to reduce the time between ozone measurements to 2 seconds, making our instrument the fastest UV-based ozone monitor on the market, while still retaining the small size, weight, and power requirements of our popular Model 202 Ozone Monitor. Fast measurements are especially desirable for aircraft and balloon measurements where high spatial resolution is needed. For 10-s averaging, a precision of 1.0 ppb is achieved. Alternatively, one can choose to average more points internally to obtain even better precision. Flash card memory and a long-life, quiet internal air sampling pump are now standard on the instrument. The Model 205 Dual Beam Ozone Monitor has been approved by the EPA as a Federal Equivalent Method (FEM) based on a modification of the Model 202: EQOA-0410-190.
Schematic Diagram
Features
- Quiet long-life internal air pump (now standard)
- Low power consumption (~8 watt)
- Internal data logger (EEPROM), logs 16,383 lines of data
- Real-time clock
- Both serial and user-scalable analog voltage outputs (4-20 mA current output optional)
- Flash card memory (SD card) for virtually unlimited, portable data storage
- Three 0-2.5 VDC analog inputs for logging other measurements, such as external temperature, pressure, and humidity
- Convenient user interface to microprocessor, including calibration parameters (gain and zero)
- Selectable measurement time of 2 s or data averaging times of 10 s, 1 min, 5 min and 1 hr (custom averaging times available)
- DewLine™ for elimination of any water vapor interference, a unique feature of 2B Tech instruments
- Dual beam feature allows for heightened precision and improved baseline stability for applications where high spatial resolution is required.
Options
- GPS for continuous logging of latitude, longitude, and altitude (for 10-s data mode and above)
- Rechargeable lithium-ion battery provides 12 hours of continuous operation
- External particle filter
- Serial-to-USB adapter
- 4-20 mA analog current output
- Bluetooth for wireless data transmission
- Low-temperature package for operation to -20 degrees C (pump, lamp heater)
- High-altitude upgrade (pressure sensor for use up to 25 km altitude)
- Extra long-life, low temperature internal air pump
- Low-power option for even lower power consumption
- Rack-mount case configuration
Applications
The fast, accurate, and precise measurements of the Model 205 Dual-Beam Ozone Monitor--combined with its portability, small size, and versatile data capabilities--have led to its use in many unique and challenging field applications. Literally from pole to pole and points in between, the Model 205 has been used aboard aircraft, balloons, ships, trains, tower platforms, remote field stations, and others. The application note here describes the use of a Model 205 on a light rail platform in Utah, resulting in some illuminating (and perhaps counterintuitive) findings about ozone levels near busy highways.
Specifications
| Measurement Principle | UV Absorption at 254 nm; Dual Beam |
| Federal Equivalent Method (FEM) | Yes, 0-500 ppb for 10-40°C: EQOA-0410-190 |
| Linear Dynamic Range | 0 to 250 ppm |
| Resolution | 0.1 ppb |
| Precision (1σ rms noise) | Greater of 1.0 ppb or 2% of reading for 10-s average |
| Accuracy | Greater of 1.0 ppb or 2% of reading |
| Limit of Detection (2σ) | 2.0 ppb for 10-s average |
| NIST-Traceable Calibration | Yes |
| Measurement Interval | 2 s (Data averaging options: 10 s, 1 min, 5 min, 1 hr) |
| Flow Rate (nominal) | ~1.8 Liter/min |
| Flow Rate Requirement | >1.2 L/min |
| Baseline Drift | < 1 ppb/day < 3 ppb/year |
| Sensitivity Drift | < 1%/day < 3%/year |
| Measurement Time, Frequency | 2 s, 0.5 Hz |
| Response Time, 100% of Step Change | 4 s, 2 points |
| Measurement and Averaging Times | 2 s, 10 s, 1 min, 5 min, 1 hr |
| Ozone Units | ppb, pphm, ppm, µg m-3, mg m-3 |
| Pressure Units | mbar, torr |
| Temperature Units | °C, K |
| T and P Corrected | Yes |
| Operating Temperature Range | 0 to 50°C standard; optional -20 to 50°C with low temperature modifications (pump and lamp heater cold-weather package) |
| Operating Altitude Range | ~0-13.5 km (150-1,013 mbar) standard; optional ~0-25 km (30-1,013 mbar) with upgraded pressure sensor |
| Power Requirement; Supplied by battery or 110/220 VAC Power Pack |
12 V dc or 120/240 V ac, nominally 650 mA at 12 V, ~8 watt (~7 watt with cell heater unplugged) |
| Size | 3.7H x 8.5W x 11.8L inches (9.5 x 21.5 x 30 cm) |
| Weight | 5.8 lb (2.6 kg); 3.1 lb (1.4 kg) without instrument case |
| Internal Data Logger Capacity | 16,383 lines (2-s fast measurement mode = 9.1 hr; 10 s avg. = 1.9 days; 1 min avg = 11 days; 5 min avg = 1.9 mo; 1 hr avg = 1.9 yr |
| SD Card Logger Capacity | > 2 GB (> 5-year capacity for 10-s averaging mode) |
| Analog Inputs for Internal Logging of Other Instruments | 3 Analog Inputs, 0-2.5 V; For example, could log external T, P, and RH |
| Data Outputs | RS232, 0-2.5 V Analog, LCD Display (Optional 4-20 mA Current; request quote) |
| Data Transfer Baud Rates | 2400, 4800, 19200 |
| Output Ranges | User-Defined Scaling Factor in Menu |
| DewLine™ | Yes |
| Quiet, Long-Life Internal Air Pump | Yes |
| Flow Meter | Yes |
| Options | Battery; External Particle Filter; Serial-to-USB Adapter; GPS (for 10-s data mode and above); Bluetooth; 4-20 mA Current Output; Cold-Weather Package, -20 to 50° C (pump, lamp heater); High-Altitude Upgrade 0-25 km (pressure sensor); Extra-Long-Life, Low-Temperature Internal Air Pump; Low-Power Option; Rack-Mount Case Configuration |
System Includes
- Model 205 Dual Beam Ozone Monitor
- Quiet, Long-Life Internal Air Pump
- AC Power Adapter (100-240 VAC to 12 VDC) with Country-Specific Plug
- Zeroing Cartridge
- Flash Card Memory for virtually unlimited, portable data storage
- SD Card (> 2 GB) and SD Card Reader
- Operation Manual on USB Stick
- Calibration Data and NIST-Traceable Calibration Certificate
- Instrument Birth Certificate
- One-Year Warranty
Confused about which ozone monitor best suits your application?
Our Tech Note #001 compares the specifications of our Ozone Monitors Models 106-L, 202, 205, 211 and POM with other high precision ozone monitors (Thermo, Teledyne-API and Ecotech).
- Decision Tree: This will help you decide which ozone monitor is best for your application.
- Comparison: See a table that compares the specifications of all of our ozone monitors.
- Applications: The most suitable ozone monitors for different applications are discussed here.
Our Tech Note #001 compares the specifications of our Ozone Monitors Models 106-L, 202, 205, 211 and POM with other high precision ozone monitors (Thermo, Teledyne-API and Ecotech).