2Btech model 205
Dual beam ozone monitor

The Model 205 Dual Beam Ozone Monitor™ was designed for even higher precision and faster response time than our popular Model 202. Data may be output as frequently as every 2 s, making it ideal for vertical profiling using balloons or aircraft measurements where high temporal resolution is required. For a given averaging time, the Model 205 has a higher precision (better than 1 ppb for 10 s averaging) and a more stable baseline than the Model 202. The Model 205 has all of the features of the Model 202 single beam instrument, including a real time clock; averaging times of 10 s, 1 min, 5 min and 1 h; an internal data logger; serial and analog data outputs; and a backup air pump to protect against data loss in the field. The Model 205 Ozone Monitor has been designated as a Federal Equivalent Method (FEM) by the EPA.
Measurement Principle | UV Absorption at 254 nm; Dual Beam |
Federal Equivalent Method (FEM) | Yes, 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 | < 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 |
Data Logger Capacity | 16,383 lines (10 s avg. = 1.4 days; 1 min avg = 10 days; 5 min avg = 1.4 mo; 1 hr avg = 1.6 yr |
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; -20 to 50 °C with low temperature modifications (rotary vane pump and lamp heater) |
Operating Altitude Range | ~0-13.5 km (150-1,013 mbar) standard; ~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, 415 mA, 5.0 watt (3.9 watt with cell heater unplugged) |
Size | 3.5 x 8.5 x 11 inches (9 x 21 x 29 cm) |
Weight | 4.7 lb (2.1 kg); 1.6 lb (0.7 kg) without instrument case |
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, External USB Converter; request quote) |
Data Transfer Baud Rates | 2400, 4800, 19200 |
Output Ranges | User-Defined Scaling Factor in Menu |
DewLine™ | Yes |
Backup Air Pump | Yes |
Flow Meter | Yes |
Options | GPS, Flash Card Memory, 4-20 mA Current Output; Lamp Heater; Rotary Vane Air Pump; Long-Life External Air Pump; Rack Mount Case |