residential air purification, odor control, and ozone treatment

Manufacturing and supplying high quality ozone generators since 1993

  Crystal Air ozone generators

Crystal Air is proud to have been a member in good standing of the International Ozone Association since  1996.





OS-4 Ozone controller
Acts like a thermostat to control ozone generators and alarms based on adjustable ozone concentration set-points. Ozone ppm readout via digital meter. Simple and inexpensive.


    Easy to install. Minimal adjustments. Sensor is in a replaceable precalibrated module. Separated by a cable, the instrument is not in the high ozone area. Sensor reading is temperature and relative humidity compensated. Replacement sensor is miniature, low cost, precalibrated and also fits our A-22. Operates from 12-24 VDC or from AC adapters available worldwide. Alarms, data loggers, and other accessories available. Programmable turn-on and turn-off set-points. Indication when .1 ppm safety standard exceeded.

Typical Applications:

  • Monitor ozone levels in treatment storage areas for fruits, vegetables, and other agricultural products. Monitor ozonated HVAC systems. General monitoring at .03-20 ppm.
  • Control the output of ozone generators using the set-point controlled relay in the OS-4.
  • Use as either ozone leak alarm or ozone failure alarm for all sizes of ozone generators.


    Range and Accuracy: .03-20 ppm of ozone. Accuracy: 10-15% (Depends on application). Temperature and humidity: 5-40c 20-95% RH Measurement Principle: HMOS (heated metal oxide semiconductor) sensor. Sensor life, sensor should be replaced after 12 months due to calibration drift. Size: 127 64 42 mm (5 2.5 1.625 in). Weight: 200 gr (7 oz) Power Requirements: 12-24 VDC, 300 mA. AC adapters available. Output control: SPDT non-latching relay. Contacts rated at 5 amps, 250 VAC. .1 ppm danger alarm: Panel LED and SPDT relay 5 amp contacts. Connections: Terminal blocks for relay output and DC input. 2.5 mm DC power jack for AC adapter. Indicators: Green LED: instrument on. Yellow LED: >.1 ppm. Red LED: generator on. Outputs: 0-2 V, 4-20mA, RS-232 digital. Case: Flame-resistant ABS with mounting ears. Not recommended for use in the presence of strong acid gases or VOC fumes.

Special order, call or email for shipping quote!  

Please note: This is a special order item made to order and will take 2-3 weeks lead time!

Model  USA$ Price qty  
OS-4 $825




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24643 21B Ave
Langley, BC
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