For over 25 years, PP Systems has been manufacturing high quality CO2
infrared gas analysers for researchers and customers from a wide variety of disciplines throughout the world. We are considered a leader in CO2
infrared gas analysis measurement instrumentation and our analysers are in use in over 100 countries worldwide. Our innovative Auto-Zero Measurement Principle ensures the greatest accuracy, reliability and long term stability that many of our customers have come to expect throughout the years. In addition, we offer a range of environmental probes for use with our analysers enhancing measurement capability.
WMA-4 CO2 Analyser
An ideal instrument for fixed installations requiring long term, continuous measurement (and control) of CO2
. A two channel version is also available.
- High precision, compact CO2 analyser
- Accuracy: <1% of span concentration over calibrated range
- Operation from AC and DC power inputs
- Built-in sampling pump and flow meter
- Automatic pressure and temperature compensation
- Voltage, current and digital (RS232) output
- Visual and audible alarm (high and low CO2)
- Rugged IP65 enclosure
- Custom, tactile keypad
- Compatible with PID controllers for control of CO2
- Integral data logging capability
Auto-Zero Measurement Principle
- Growth chambers
- Environmental control rooms
- Open top chambers (OTCs)
- Greenhouses and nurseries
- Fruit storage
- FACE sites
- CO2 leakage monitoring
- Indoor air quality and safety
- Industrial monitoring
All PP Systems' CO2
infra-red gas analysers feature the Auto-Zero facility. This feature, which occurs at regular intervals, allows for fast warm-up, adaptation to changing ambient conditions and excellent stability of the CO2
signal. The action of auto zeroing minimises the effects on span (gas sensitivity) of sample cell contamination, source aging, changes in detector sensitivity and changes in pre-amplifier gain.
Based on our extensive in-house testing, we concluded that true Auto-Zero instruments such as ours provided greater stability and reliability for the following reasons:
- Major effects of temperature are on the transmission characteristics of the interference filters and in 2 wavelength instruments, these are required to closely track.
- Dirt in the cells, changes in cell reflectivity, changes in source position or relative emission over the source surface can differentially affect the sensors.
- Changes in source temperature will affect the relative emissions at the two wavelengths.
- Cross sensitivity problems to other gases are increased as neither wavelength must be affected.
- Both sensors will require electronics and these must have identical temperature coefficients and must age exactly the same.
- Reliability must decline as the component count increases.
- Using two sensors degrades the signal/noise which is inversely proportional to the sensor area.
Therefore, for the reasons described above, we believe that the Auto-Zero measurement technique is best for all applications that demand the accuracy, reliability and long term stability.
WMA-4 CO2 Analyser product brochure