Dissolved Ozone Meter & Controller - AS-500


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California Regulatory Information

SKU: 007647
3.8" x 3.8" x 3.3"
2 lbs.

Product Overview

AquaSensors Gas Monitoring

The AS-500 is a very versatile ozone meter that can be used in many different applications. The sensor can work at pressures from 0 - 30 PSI. This allows the sensor to be used in-line with no extra flow cell!  

What makes the AS-500 different?

The AS-500 has a leg-up on other dissolved ozone monitors because of it's rugged no-nonsense sensor probe. It is not a high-precision instrument when compared to some other meters, but most dissolved ozone meters require very tightly controlled water pressure and flow in order to achieve accuracy whereas the AS-500 does not. The probe can be installed directly into water piping and operate reliably and consistently without being overly sensitive to changes in pressure and flow.


  • Recommended for Ozone Concentrations 1 PPM & higher
  • Our most reliable dissolved ozone meter and controller
  • Displays ozone level and water temperature
  • Relay outputs for control abilities
  • Can be installed in a process line
 More Information
 Weight 2.0 lbs (0.91 kg)
 Electrical Native Power 24 VDC 0.25 A Available Option 90 - 250 VAC 50/60 Hz external adapter
 Dimensions 3.8 x 3.8 x 3.3 inches (9.5 x 9.5 x 8.3 cm) display only
 Warranty 1 Year
 Display Digital
 Detection Method Amperometric
 Temperature Range 32 to 122°F (0.0 to 50°C)
 Range 0 - 10 ppm (0 - 10000 ppb)
 Accuracy +/- 1%
 Resolution 0.01 ppm (10 ppb)
 Supporting Documents AV-88 User Manual; AnalogPlus Dissolved Ozone Sensor Instruction Manual
 Response Time 1 second
 Fluid Connection 1 Inch MNPT
 Materials Wetted Viton® FEP/PTFE flouropolymer
 Max Ops. Water Pressure 30 PSI (2.11 Bar)
 Max Water Pressure 60 PSI (4.22 Bar)
 Min Detect Limit 0.1 ppm (100 ppb)
 Internal Datalogging No
 Display Units ppm
 Comm. Protocol None
 Relays 2

Additional FAQ's

What replacement parts are needed?

The only replacement parts are the membrane & electrolyte solution.

Where is the AS-500 manufactured?

The AS-500 dissolved ozone monitor is made in the USA.

Does water quality affect electrolyte solutions replacement frequency?

The electrolyte replacement frequency is not directly dependent on water quality. However, higher dissolved ozone levels in the water will consume the electrolyte faster, poor water quality usually requires higher dissolved ozone levels, therefore the electrolyte would be consumed faster. Water quality normally only affects the life of the membrane cap.

What is the relationship of ORP (Oxidation Reduction Potential) to Dissolved Ozone?

There is no direct relationship of ORP levels to dissolved ozone levels. ORP is measuring the cleanliness of the water, or the oxidation potential of the water. This is usually a measure of the oxygen, or even ozone in the water. So, it is true that there is a correlation of ozone to ORP, however, depending upon water quality this relationship will vary from water to water. 

How do I calibrate my dissolved ozone monitor?

Unlike most ambient air ozone monitors which can be sent back to Ozone Solutions for calibration, dissolved ozone monitors should instead be calibrated at the customer site for best results. The industry standard for calibrating dissolved ozone monitors generally accepts chemkits or single analyte meters as valid references to calibrate against. For further detail, refer to our K-7404 or I-2019 products, which are listed on the Dissolved Ozone Monitors page.

Can the AS-500 handle saltwater?

This unit has not been tested in saltwater. We think the sensors would not be reliable in that type of application due to high ionic strength/salt concentration and unknown levels of dissolved organics and suspended particles. e.g., membranes clog up easily in some of those conditions. The unit we recommend for saltwater is the DOM-1. The sensing technology in the DOM-1 does not come into contact with the saltwater.

What is the maximum cable length between the probe & display?

The maximum cable length is 100-ft. The cable is shielded to eliminate EMF interference.

How often does this monitor require calibration?

The manufacturer recommends a yearly calibration. The readings of all ozone monitors will start to stray over time and need to be corrected when possible.

How long will the replacement parts last on the AS-500 dissolved ozone monitor?

The electrolyte solution should be replaced every 3-6 months. The membrane should be replaced every year, or as necessary. This will occur more frequently in water with higher turbidity, TSS or high dissolved ozone levels.

Warranty Information

Seller warrants that all Products will conform to the Specifications and will be free from defects in material workmanship and programming. Claims for Products not complying with this warranty shall be submitted by Buyer no later than 12 months from delivery date to Buyer. Seller shall promptly repair or replace, at its option and expense, non-complying Products. The shipment of non-complying Products by Buyer to Seller, and the return shipment of repaired or replacement Products by Seller to Buyer shall be at Seller's expense, unless it shall be determined that Buyer returned a Product that was in compliance, in which case such cost shall be borne by Buyer and, if paid by Seller, these expenses shall be reimbursed by Buyer within thirty (30) days of notice by Seller. Buyer shall receive a credit for any non-complying Products returned for repair or replacement. All non-complying Products shall be returned to Seller (at its offices or as otherwise instructed) no later than 30 days as of the date the non-compliance of any such Product has been discovered. Seller is NOT responsible for any/all damages suffered to the Products that is caused by the Buyer. Such as but not limited to damage by wrong electrical current, damage through crush or dropping the product, damage through untrained users of Product, damage through improper operations.

California Regulatory Warning

Example Image
Use in unoccupied spaces only.
Health hazard warning: emits ozone.

This product is not CARB Certified (Ozone Emissions for Air Cleaners).
Product Disclaimer: Does not meet California air cleaner regulation requirements; cannot be shipped to California.