Field-installation type pH meter

HORIBA's long-selling water quality meter that excels in both indoor and outdoor applications.

Suitable for pH monitoring and control in various production processes, as well as wastewater treatment and other applications. We offer a wide range of electrodes and cleaning devices to accommodate a variety of samples.

Division: Process Water
Manufacturing Company: HORIBA Advanced Techno Co., Ltd.

Lineup of a wide range of electrodes

A wide variety of electrodes are offered to cater to different needs.

Comprehensive range of cleaning devices.

A diverse lineup of cleaning devices are offered.  Particularly, ultrasonic cleaners are advantageous as they do not require water or air, making them convenient for retrofitting existing HP-200 installations on site. The drop-in type of cleaning device, which fits into a holder, offers ease of maintenance.

Product namepH meter
Glass electrode
Measurable rangepHpH0 to pH14 (display range: pH−1 to pH15)
Temperature0℃ to 100℃
  • Display range : −10℃ to 110℃(the sensor types are detected automatically)
  • Display range : −20℃ to 130℃(the sensor types are input by manually)
resolution capability
pH0.01 pH
EfficiencypHRepeatabilityWithin ±0.03 pH (response for equivalent input)
LinearityWithin ±0.03 pH (response for equivalent input)
TemperatureRepeatability±0.3℃ (response for equivalent input)
Linearity±0.3℃ (response for equivalent input)
Number of outputs2 (the negative terminals for transmission outputs are internally connected and at the same electric potential)
Output type4 mA to 20 mA DC: input/output isolated type
Load resistanceMax: 900Ω
LinearityWithin ±0.08 mA (output only)
RepeatabilityWithin ±0.02 mA (output only)
Output rangeOutput 1pH: Selection from preset ranges or free range input within measuring range.
Output 2Temperature: Free setting within a range between −20℃ and 130℃
Occasional out for errorHold or burnout to either 3.8 mA or 21 mA
Transmission holdIn the maintenance mode, transmission signal is held at the latest value or preset value.
In the calibration mode, transmission signal can be alive or held.
Contact outputNumber of output5
Output typeNo-voltage contact output
Contact typeRelay contact; SPDT (1c)
Contact capacity250 V AC, 3 A; 30 V DC, 3 A (resistance load)
R1, R2Selectable from upper limit alarm, lower limit alarm, ON/OFF control, and time-sharing proportional control.
R3, R4Selectable from upper limit alarm, lower limit alarm, ON/OFF control, currently holding of transmission output, and cleaning output.
FAILError alarm
Alarm setting range
  • Setting range: 0.00 pH to 14.00 pH
  • Delay time: 0 seconds to 600 seconds
Control functionON/OFF
  • Setting range: 0.00 pH to 14.00 pH
  • Control width: 0.02 pH to 4.00 pH (−0.01 pH to 2.00 pH)
  • Setting range: 0.00 pH to 14.00 pH
  • Proportional band: 0.02 pH to 4.00 pH
  • Period: 5 seconds to 300 seconds
  • Control duty ratio shift function: 50% to 100% at the alarm setting point.
  • Variable off time extension in the F-zone: When the deviation enters a certain range (Fine-zone), the off time of the duty is automatically extended accordingly.
    This function is disabled when the duty ratio shift function is enabled.
  • F-zone: 1% to 100% of proportional band (when the deviation enters the above range, the automatic off time extension is enabled.)
  • Max. off time extension: 0 second to 300 seconds
  • Max. duty setting: 50% to 100% (regardless of the proportional band)
Cleaning outputNumber of outputs1
Output typeAC power control output (applied power supply voltage)
Contact typeRelay contact, SPST (1a)
Contact capacity250 V AC 0.5 A
Contact functionSolenoid valve for cleaning control
SettingsCleaning period0.1 hours to 168.0 hours
Cleaning time2 seconds to 600 seconds
Hold time2 seconds to 600 seconds
Timer accuracyWithin 2 minutes per month
Description of cleaning

One of the following operations.
Operation of internal timer only
Operation of internal timer and external input command
Enable the internal timer only when external input is active.
The cleaning trigger signal (the external trigger signal must be longer than 2 seconds).

Contact inputNumber of inputs1
Contact typeNo-voltage "a" contact for open collector
ConditionsON resistance: 100 Ω max.
Open voltage: 24 V DC
Short-circuit voltage: 12 mA DC max.
Contact functionExternal input for cleaning or transmission holding if cleaner is not attached.
Communication methodRS-485
Signal type2 wire system, isolated from the input circuit
Not isolated from transmission circuit
Applicable temperature
Platinum resistor: 1 kΩ (0℃)
Normal characteristic temperature-sensitive resistor: 500 kΩ (25℃), 6.8 kΩ (25℃),10 kΩ (25℃)
Element selection methodAutomatic temperature sensor type detection or manual selection (no temperature element is selectable)
Temperature compensation
0℃ to 100℃
Temperature calibration1 point calibration comparing reference thermometer
CalibrationCalibration methodAuto or basic (manual) calibration
Number of calibration pointsSelectable from 1, 2, and 3 points
Kinds of standard solutionspH 2, 4, 7, 9, and 10
Any pH standard solution (with difference of 2 pH or more) for basic calibration
Additional capabilitiesAutomatic detection of kind of standard solution
Automatic detection of electric potential stability
Automatic detection of calibration failure (asymmetry potential, sensitivity, or response time)
Calibration history (asymmetry potential, sensitivity, and number of days elapsed after last calibration)
Self-checkCalibration errorAsymmetry potential error, sensitivity error, and response time error
Temperature calibration error
Standard solution detection error
Electrode diagnostic errorCracking of glass response membrane
Reference electrode impedance error (only applicable for differential circuit mode with a liquid ground electrode)
Temperature sensor short-circuit, temperature sensor disconnection, and deviation from temperature measurement range
Meter errorCPU error, ADC error, and memory error
Operating temperature range−20℃ to 55℃ (without freeze)
Operating humidity rangeRelative humidity: 5% to 90% (without condensation)
Storage temperature−25℃ to 65℃
Power supplyRated power supply voltage100 V to 240 V AC ±10% 50/60 Hz
Power consumption15 VA (max)
OthersWith power switch for maintenance use
CE markingEMC    :EN61326-1
     Class A, Industrial electromagnetic environment
Safety   :EN61010-1
RoHS   :EN50581
      9. Industrial monitoring and control instruments
FCC rulesPart15 Class A
StructureInstallationOutdoor installation type
Installation methodMount on 50 A pole or wall
Protection codeIP65IEC60529, JIS C0920
Case materialAluminum alloy (coated with epoxy-denatured melamine resin)
Material of fittingsSUS304
Material of hoodSUS304 stainless steel (coated with epoxy-denatured melamine resin)
Material of windowPolycarbonate
Display elementReflective monochrome LCD
External dimensions180 (W) mm × 155 (H) mm × 115 (D) mm (excluding the fittings)
MassMain body: Approx. 3.5 kg
Cover and fittings: Approx. 1 kg
  • *1  :The standard for effect on the reading by the electromagnetic field of the radiated radio frequency and by the conducted interference is within the measured pH value ±0.25pH.
  • *2  : When the sensor cable, the transmission cable, or the contact input cable is extended by 30 m or more, the surge test under the EMC Directive for CE marking is not applied.


An arrester (spark over voltage: 400 V) is implemented for transmission output, contact input, and communication. However, use a most suitable surge absorption element on the connection lines in accordance with the ambient environment, the situation of equipment installed, and the externally connected equipment.

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