Q46/85 Peracetic Acid Monitor from ATI


Peracetic acid (PAA) is an extremely strong oxidizer widely used in the food industry for disinfection of piping systems and processing equipment. It is also used for spray washing of food products and for disinfection of cooling water systems. As a disinfecting agent, PAA is often preferred because it produces no harmful breakdown products.

As with any disinfection system, maintaining proper residual values is the key to effective pathogen control. To facilitate reliable chemical feed control, ATI has developed an on-line monitor cable of providing real time measurement of low levels of PAA in solution. The Q46/85 Peracetic acid monitor uses a direct sensing polarographic probe mounted in a flowcell to measure PAA residuals in a flowing water stream. A permeable diffusion membrane isolates the sensing electrodes from the measured sample, providing long term stability without electrode fouling problems. The measurement is selective for PAA and is not affected by changes in hydrogen peroxide in solution.

Peracetic acid sensors are amperometric devices isolated from the water by a permeable membrane. As PAA diffuses through this membrane, it comes in contact with an active electrode and is reduced on the surface. The net effect is that the sensor generates a current proportional to PAA concentration. An integral RTD in the sensor provides for automatic temperature compensation, allowing the sensor to operate accurately over a range of 0-50°C.

Peracetic acid sensors are capable of operating over a fairly broad concentration range, from a low range of 0-20 ppm up to a high range of 0-2,000 ppm. Systems will operate with good sensitivity down to 0.2 ppm and respond to changes in concentration within about 60 seconds, making them useful for automatic control.


  • Programmable range options from 0-2 ppm up to 0-200 ppm provide maximum application flexibility
  • Power options include universal 90-260 VAC or 12-24 VDC
  • Two isolated 4-20 mA outputs are standard, with an option for a third output if required. Default setting provides analog outputs for PAA and temperature
  • Standard PID control function assignable to one analog output
  • Available in either Profibus-DP, Modbus-RTU, Modbus-TCP/IP, Ethernet-IP
  • Three SPDT relays are standard, with relay functions programmable for alarm, control or trouble indication. Three additional low power relays available as an option.
  • NEMA 4X (IP-66) enclosure is suitable for wall, pipe or panel mounting
  • Back-lit LCD display provides clear visibility in any lighting conditions. A scrolling second line on the display provides additional information and programming prompts.

Peracetic Acid sensors require a steady flow of sample across the membrane at the tip of the sensing assembly. Options for flowcells, including the standard constant-head overflow systems and a sealed flowcell for pressures up to 50 psi. For simplicity of installation, complete flow control assemblies are available. Panel assemblies re available with or without a flow switch and can greatly reduce installation time. For open tank installation, a submersible sensor is available. Sample agitation is required as PAA sensors cannot be used in still water.


Range 0-20.00 ppm, 0-200.0, 0-2000 ppm
Accuracy ±0.3 pm or 2% of full scale
Repeatability ±0.1 ppm
Non-Linearity 0.1% of selected range
Temperature 0.01% of span/°C
Power 90-260 VAC, 50/60 Hz, 10 VA maximum
12-24 VDC, 500 mA maximum
Relays Two isolated 4-20 mA, 500 Ω load maximum, 3rd output optional
Display 4 digit, 0.74″ numberic LCD with 12 character second line, LED back light
Enclosure NEMA 4X (IP-66) Polycarbonate, V-0 fammability
Operating Temperature -40 to 60°C
Weight 6 pounds
Zero Drift < 0.01 ppm/month


PAA Sensor Membrane covered polargraphic
Materials PVC
Response Time 90% in 60 seconds
Temperature 0-50°C
Pressure Limit 0-50 psig
Sensor Cable 25′
Sensor Flowcell Clear acrylic constant head overflow or sealed acrylic flowcell
Sample Flow Rate 5-15 GPH (0.3-1.0 LPM)

Ordering Information

For pricing please call AFC International at 800-952-3293, 219-987-6825 or fax 219-987-6826 or email sales@afcintl.com.


Q46-85 Peracetic Acid Monitor Literature

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