Q46H/64 Ozone Meter

Dissolved Ozone Monitor, Measure ozone with ppb resolution or, up to 200 ppm.  4-user selectable ranges.

Integrated PID loop, relays, and 4-20 mA output signals.

Ozone Information

pH sensor range: 0-14



Online Monitoring & Control for Ozonation Systems:

 The q46H/64 Dissolved Ozone Meter provides accurate and reliable ozone monitoring and control for your ozone treatment systems.  The Q46H offers a variety of output including a 4-20mA output (x2), PID control, three adjustable relays, and digital communications. 

There are 4 User Settable Ranges to choose from on q46 Ozone Monitor:

  • 0-200 ppb (1 ppb resolution)

  • 0-2.000 ppm (0.001 ppm resolution)

  • 0-20.00 ppm (0.01 ppm resolution)

  • 0-200.0 ppm (0.1 ppm resolution)

All ranges are user settable with display panel on the q46.


q46H/64 Ozone Monitor Specifications:

Sensor Type

 Membrane-covered Polargraphic (flow type or submersible)


 0-200.0 PPB, 0-2.000 PPM, 0-20.00 PPM, 0-200.0 PPM (mg/l)

Response Time

 90% in 60 seconds


 ± 0.01 PPM


 ± 0.01 PPM

Zero Drift

 < 0.01 PPM/month

Analog Output

Two isolated 4-20 mA, 500 Ώ load max. (3rd output optional)

Relay Output

Three SPDT, contacts rated 6 amp @ 250 VAC, 5 amp @ 24 VDC (3 additional low power SPST non-isolated relays optional)

Operating Conditions

 0-60-deg C


 NEMA 4X (IP-66) Polycarbonate, V-0 flammability


 4 digit, 0.75” numeric LCD with 12 digit second line, LED back light


 6 lbs. (2.7 Kg), includes flowcell and accessories 

Wetted Materials

 PVC and Titanium

Sensor Cable

 25 ft. (7.5 m) standard, 100 ft. (30 m) max. with junction box

Sample Temperature

 0-50° C

Sample Pressure

 0-50 PSIG (Pressure controlled to fixed value)

Temperature Sensor

 Internal Pt100 RTD

Flowcell Materials

 Acrylic with barb fittings

Sample Flowrate

 7-15 GPH (0.5-1.0 LPM)

Sample Connections

 1/4” I.D. hose barb inlet, 1/2” I.D. hose barb drain for standard flowcell


 CE marked to BS EN 61326-1:2006 Standard UL and CSA General Purpose


 4.4”H x 4.4”W x 3.5”D (111 x 111 x 90 mm)

Mounting Options

 Wall or pipe mounting bracket supplied

Conduit Entry

 Two PG-9 cord grips, 0.16-0.31” diameter cable

Ambient Temperature

 Operating: -40° to + 60°C Storage: -40° to + 70°C

Ambient Humidity

 0-95%, Non-condensing


  • All systems are supplied with one package of membranes, one 120 cc bottle of electrolyte, and one spare parts kit containing 3 each of all o-rings and special screws

  • Flowcell for Dissolved O3 / pH Combo system should be kept within 25’ for monitor.


q46H/64 Features:

  • Wide Detection Ranges - User Settable ranges from 0-200 PPB up to 0-200 PPM provide maximum application flexibility.

  • AC or DC Power Options - Power options include universal 100-240 VAC or 12-24 VDC

  • Analog Output -  Two isolated 4-20 mA outputs are standard, with an option for a third output if required. Default setting provides analog outputs for ozone and temperature.

  • PID Output - Standard PID control function assignable to one analog output.

  • Relay Outputs - Three SPDT relays are standard

  • Clear Display - Back-lit large LCD display provides clear visibility in any lighting conditions. A scrolling second line on the display provides additional information and programming prompts.

  • pH Input Option - Enables monitor to measure both ozone and pH. One analog output may be assigned to the pH measurement, allowing remote monitoring and recording of both ozone pH simultaneously.

  • Flexible Mounting - NEMA 4X (IP-66) enclosure is suitable for wall, pipe, or panel mounting.


Sensor & Flowcell Options:

 Dissolved Ozone sensors require a steady flow of sample across the membrane at the tip of the sensing assembly. ATI offers a number of options for flowcells, including the standard constant-head overflow system, a sealed flowcell for pressures up to 50 PSI, and a low-volume flowcell where low sample flow is important. A 1-½” flow tee is also available for in-line applications with reliable constant flow and pressure conditions. For simplicity of installation, complete flow control assemblies are available.

Sealed Flowcell

The sealed flowcell allows for a controlled flow of water that can then be pushed under slight pressure to a drain location.  Water flow must be well controlled externally to a flowrate of about 400 cc/min.  Variable flowrate or pressure will cause unstable readings in the sealed flowcell.  A special flow control element can be purchased ahead of this device.  It is part number 55-0048.

Slight pressure, up to 2 PSI is acceptable on the cell to allow water to drain to a remote location through tubing.

Constant Head Flowcell

The dissolved ozone sensor will provide the best performance when used with the constant-head flowcell.  When monitoring ozone levels below 0.5 ppm this method should always be used.  Water pressure on the sensor and water flow are automatically controlled via the gravity flow chambers in the flowcell.  Water flows of 400 - 500 cc/min will be used.

Low-Flow Flowcell

Low-flow sensor flowcell is used to reduce the amount of water used for ozone detection in water. This is a great option for applications where low water flow rates are required. Sample water flow rates of 150 – 300 cc/min can be used with the low-flow flowcell.

Passages in the low-flow flowcell are very small, therefore, clean water is required. Flow rate can be measured and controlled by a rotometer installed on the inlet side of the flowcell. Water flow should not vary more than 5 cc/min.

Flowcell Sensor

The Flowcell Sensor is used for each of the flowcell systems shown above. There are threads on the sensor body that allow the sensor to thread into the low-flow sensor flowcell and the sealed flowcell. The long smooth end will fit snugly in the constant-head flowcell and seal with o-ring seals integrated into the constant-head flowcell.

Submersion Sensor

For submersible applications we offer the submersion sensor. This sensor can be dropped into a tank of water for ozone measurements in water. This sensor could also be mounted into the side of a tank permanently.

Ensure no more than 2-3 PSI of water present is pressure on the sensor at any time. Water pressure must also be consistent for accurate measurements of ozone in water.




The q46H Ozone Sensors must be calibrated on-site with the customers' water in process. As pressure and water flow will affect the calibration it is important to perform the calibration in the specific process the sensor will be used to measure ozone in.

Calibration frequency will depend upon ozone concentration in the water and water quality. Higher dissolved ozone levels will consume the electrolyte solution and membrane quality quicker than low levels of ozone. At ozone levels below 2.0 ppm we find the q46H can maintain stable readings for 6-months at a time between calibrations. However, at ozone levels greater than 20 ppm calibration should be performed at least monthly and ozone levels greater than 100 ppm will require weekly or even daily calibration.

A bottle of electrolyte solution and a pack of 10 membranes is shipped with each q46H Dissolved Ozone Meter.

Parts kit shipped with every Q46H dissolved ozone meter

Calibration should be performed with a colorimetric dissolved ozone test kit. Below are a few kits we suggest and the potential applications for each.


I-2022 SAM Dissolved Ozone Meter

Best for low level detection of ozone, below 0.75 ppm


I-2022 Dissolved ozone test kit for calibration


 I-2019 SAM Dissolved Ozone Meter

Best for high level detection of ozone, direct read to 5.0 ppm


Dissolved ozone meter calibration kit




Q46H/64 Dissolved Ozone Monitor Brochure

Q46H/64 Typical Specs

Q46H/64 Manual

Q46H/64 System Diagrams 

Ozone Information

More Information
Manufacturer ATI
Call For Price No
Gas Ozone (O3)
Listing Description

Measure and control ozone process.  Dissolved ozone meter with 4-20 mA output, PID controller, 3 Relay outputs, and digital communications (Same as Q45H but with 3 control functions listed)

4-20 mA Output Yes
Relays 2 Alarm Relays + 2 Control Relays
Voltage Output None
Power Requirements 12-30 VDC, 120 VAC or 220 VAC 50/60 hz. please specify desired voltage when ordering
Datalogging No
Warranty 1 Year
Range 0 - 200 ppb, 0 - 2.00 ppm, 0 - 20.00 ppm, 0 - 200.0 ppm
Write Your Own Review
You're reviewing:Q46H/64 Ozone Meter
Your Rating