Model 205 Dual Beam Ozone Monitor

Dual-beam UV absorption at 254 nm with two detection cells to improve precision, baseline stability, and response time. Lightweight with low power consumption and a quiet, long-life internal air pump. For research and monitoring applications where high precision and fast responses required.

0-250 ppm measurement range with 1.0 ppb precision
Dual beam for heightened precision and fast measurements
2-second measurement frequency (fastest available on the market)
Approved by the EPA as a FEM: EQOA-0410-190

PRODUCT DETAILS
Product Details

Description

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

Product Details

Makes use of two detection cells to improve precision, baseline stability, and response time
UV light intensity measurements Io (ozone-scrubbed air) and I (unscrubbed air) are made simultaneously
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
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
Rackmount configuration available as an optional upgrade