Air Quality

Measurement Instrumentation for Air Quality Monitoring

Campbell Scientific's systems for unattended, long-term monitoring of air quality parameters provide unmatched reliability and versatility. Our systems measure ambient gas and particulate concentrations, stack emissions, and visibility. Meteorological parameters can also be monitored for use in determining air stability or for use in air quality modeling and dispersion modeling. Our equipment is in use at smelters, refineries, tailings, mines, landfills, construction sites, manufacturing and processing plants, and industrial and hazardous waste sites. Systems can be customised using a wide selection of data loggers, sensors, analysers, and communications devices.

System Benefits

Meteorological measurements can meet EPA's PSD guidelines.
Systems are compatible with a variety of third-party gas analysers, visibility sensors, and particulate monitors.
Systems are compatible with continuous emission monitoring (CEM) sensors such as flow rate, opacity, temperature, and pressure.
Systems can monitor efficiency of pollution abatement systems.
Station portability allows optimal siting and even relocation if necessary.
An entire network of field stations can be monitored from a single PC via wireless communications.
Powerful onboard instruction sets provide measurements and auto-calibrations specific to each gas analyser and site.
A network of 20 monitoring stations can be polled every 60 seconds allowing real-time decision making to satisfy public health concerns.
Monitoring systems can incorporate other measurements, such as water quality, slope stability, and leak detection.

Data Loggers

Our monitoring stations are based around a programmable data logger (typically a CR10X or CR23X) that measures the sensors, then processes, stores, and transmits the data. Our low-power data loggers have wide operating temperature ranges, programmable execution intervals, onboard instructions, and ample input channels for commonly used sensors. Wind processing algorithms, including the Yamartino method of computing standard deviation of wind direction, are standard in the data logger instruction sets. Our data loggers interface directly to most sensors, eliminating external signal conditioning.

Data are typically output in the units of your choice (e.g., wind speed in mph, knots, m/s). Measurement rates and data recording intervals are independently programmable, allowing calculation of 15-minute, hourly, and daily data values from 1-minute or 1-second measurements, for example. Atypical events can trigger alarms and cause additional data to be recorded. The program can be modified at any time to accommodate different sensor configurations or new data processing requirements. Channel capacity can be expanded using multiplexers.

Sensors, Analysers, & Monitors

Almost any meteorological sensor can be measured by our data loggers, allowing stations to be customised for each site. Typical sensors used on our stations include, but are not limited to: wind speed, wind direction, solar radiation, delta temperature (SRDT), air temperature, water temperature, soil temperature, relative humidity, precipitation, and barometric pressure. In some locations, hydrological sensors provide additional measurements, such as water quality of a nearby stream.

A wide range of gas analysers can be used with our systems. Many gas analysers output a user selectable 1, 5, or 10 Vdc signal proportional to the concentration of the gas being measured. The data logger measures the voltage directly and then scales the voltage into the appropriate concentrations, in ppm or ppb. Control ports on the data logger are programmed to open and close solenoids to complete the daily self-calibration. Commerically available gas analysers measure concentrations of SO2, H2S, O3, NOX, NO, NO2, CO, CO2, CH4, and THC (total hydrocarbon).

The beta-gage type of particle sampler (PM10 or PM2.5) typically has a voltage output that our data loggers can measure directly. Our data loggers can also measure most flow sensors and opacity meters. On-board processing instructions use concentration and flow data to compute stack emissions.

Sensors we offer include the 05103 for wind speed and direction, the LI-200X or CMP3 for solar radiation, and the 107-L for air temperature.

For a list of manufacturers of gas anayzers, particle samplers, and visibility sensors, go to "Air Quality Links" above.

Data Retrieval

We offer multiple communication options for data retrieval which can be mixed within the same network. Telecommunication options include short-haul, telephone (landline, voice-synthesized, cellular), radio frequency, multidrop, and satellite. On-site options include storage module, and laptop computer.

Software

Our PC-based support software simplifies the entire monitoring process, from programming to data retrieval to data display and analysis. Our software automatically manages data retrieval from networks or single stations. Robust error-checking ensures data integrity. We can even help you post your data to the Internet.