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-300 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 when automatic detection capability for each temperature
sensor type is used: −10℃ to 110℃
Display range when temperature sensor type is manually set: −20℃ to 130℃
pH0.01 pH
PerformancepHRepeatabilityWithin ±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)
Output type4 mA to 20 mA DC: input/output isolated type
Load resistanceMaximum: 600Ω Case of 24 V DC power supply (*Note 1)
LinearityWithin ±0.08 mA (output only)
RepeatabilityWithin ±0.08 mA (output only)
Output rangepH: Selection from preset ranges or free range input within measuring range.
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 inputNumber of input points1
Contact typeNo-voltage "a" contact for open collector
ConditionsON resistance: 40 Ω 
Open voltage: 1.2 V
Short-circuit current: 21 mA DC max.
Contact functionExternal input for transmission holding.
Applicable temperature
Platinum resistor: 1 kΩ (0℃)
Positive relation resistor with temperature
:500 Ω (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, 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, ADC, and EEPROM errors
Operating temperature range−20℃ to 60℃ (without freeze)
Operating humidity rangeRelative humidity: 5% to 90% (without condensation)
Storage temperature−25℃ to 65℃
Power supplyRated voltage24 V DC (operating voltage range: 21 V to 32 V DC) (*Note 1)
Power consumption0.6 W max.
CE markingCompatible
EMC directiveEN61326-1
RoHS DirectiveEN50581
ImmunityIndustrial electromagnetic environment
Electostatic dischargeIEC61000-4-2
Electromagnetic field of radiated
radio frequency
IEC61000-4-3 (*Note 2)
Electric fast transient/burstIEC61000-4-4 (*Note 2)
SurgeIEC61000-4-5 (*Note 3)
Conducted interference induced
by radio frequency
IEC61000-4-6 (*Note 2)
EmissionClass A
Radiated disturbanceCICPR 11 CLASS A
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 mounting brackets)
MassMain body: Approx. 2.8 kg
cover and mounting brackets: Approx. 1 kg


  • Note 1:  The maximum load resistance is available within the range shown in the figure below, depending on power supply voltage:


Relation between power supply voltage and load resistance

Relation between power supply voltage and load resistance

  • Note 2:  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 0.1 pH.
  • Note 3:  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.
  • Note 4:  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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