Calibration Free pH Sensors

  • No Calibration Required Unlike other pH sensors that need frequent re-calibration, ANB's patented technology means that the sensor requires no calibration throughout its lifespan
  • Full Salinity Range No calibration required
  • Temperature Measurement Onboard temperature measurement
  • Easy to Use Low maintenance
  • All Models IP68 Certified
Product Options
Flow Cup Adapter
Integration Kit
AQ5 Spare Transducer
AQ50 Spare Transducer
OC300 Spare Transducer
OC1250 Spare Transducer
Data Transfer Unit


These intelligent and easy to use, calibration-free sensors, are ideally suited for use in any sensing platform in freshwater, marine, estuarine, saltwater and aquaculture applications. These solid state sensors provide pH, conductivity and temperature measurements.


  • Calibration-free - ANB’s patented technology ensures that the sensor is automatically calibrated in-situ
  • Biofouling – designed to stop biofouling as standard
  • Storage – can be stored wet or dry without
  • Data storage – an onboard 8 Gb memory allows storage of over 15 million sensor readings of pH, conductivity, and temperature.
  • Cost effective

AQ Range for Aquaculture & Freshwater

AQ5 - Calibration-free pH sensor for up to 5 m depths. Supplied with 1 m cable as standard (no data transfer unit included)

OC Range for Oceans & Coastal Monitoring

OC300 - Calibration-free pH sensor for up to 300 m depths. Supplied with data transfer unit and 0.6 m cable as standard

OC1250 - Calibration-free pH sensor for up to 1250 m depths. Supplied with data transfer unit and 0.6 m cable as standard

Manufactured by: ANB Sensors
Model: Calibration Free pH Sensors

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


AQ5 Specifications
pH Range 2-10
Resolution 0.01
pH Accuracy +/- 0.05 pH
Response Instantaneous
Salinity 0 – 40 ppt
Temp Sensor to 0.1C
Depth Rating 5 m
Operational Temp -5 to 40C
Dimensions 41 x 191 mm
Weight in Air 0.26 Kg
Weight in Water 0.04 Kg
Physical Comms RS232/485
Comms Protocols Modbus, Terminal
Power Supply 24VDC
Current 75mA
Display LCD 5 Digit
Interface 4 Button Keypad
Memory Non-volatile
Logging Manual/Automatic
Logs 100
Special Features Security Lockout
Certification CE
Warranty 3 Years
Accessories None




  1. 1. Modbus protocol commands enabled: the command protocol is now operational and has been updated to take into account a number of the new features.
  2. 2. Transducer Health status enabled: the sensor now actively tracks numerous internal analytics on the sensors measurement sweep and examines if these have passed or failed the health criteria. This is then translated to the transducer health output.
  3. 3. Sensor error message updated: The three error messages that the sensor will output have been updated to numeric outputs.
  4. 4. Sensor diagnostics status is enabled: This highlights issues with the internal operation of the sensor.
  5. 5. Download: The downloadable data from the internal memory now matches that displayed on the telemetry system. This is to provide the end-user with exact replicas of the two data streams and has been done to future-proof the sensors as we build into the firmware further measurement parameters.
  6. 6. Sensor output updated: In the last reserve space of the current sensor output the file number to which the data is saved in the internal memory is displayed. This will allow customers to download specific sets of data.
  7. 7. RTC: The sensor can now be run without needing the time set. This follows a request from customers who would like to switch the sensor on and take a measurement using the ScanO1 command and ignore the sensors time and having to set the clock based on their local time.
  8. 8. Internal functions of sensor: The internal operation of the sensor has been upgraded to control the sensors' measurement protocols in a more efficient manner, thus providing longer-term stability and accuracy of the sensors transducers. Improved data output, enhanced data accuracy, bug fixes, allows single measurement.