Field-installation Type Electric Resistivity Meter (Two-Wire Transmission)

HE-300R connects resistivity sensor (ERF Series) and measures resistivity and temperature in the sample water.It is suitable for measurement of UPW resistivity.

Measurement range

Resistivity 0.00 - 20.00 MΩ・cm, 0.00 - 200.0 kΩ・m
Temperature: 0.00 - 100.00 ℃

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


  • Responds to harsh conditions at the site process
      Operating temperature range(Transmitter):-20 - 60℃
      Rated voltage: DC24V
      Robust aluminum die cast (Protection code:IP65)
  • CE Marking and FCC Compliance suitable for use at overseas sites



  • Convenient function to display liquid temperature at the same time(Transmission output available)
  • Sensor error can be detected immediately by self-diagnosis function
  • Designed to be environmentally friendly (Pb-free) in response to WEEE and RoHS
  • Flexible temperature compensation


Easy maintenance

  • Easy to view big display
  • Easy operation
  • Calibration log memory
  • Screw terminals that do not fall off are used in the terminal block for wiring
Product nameResistivity meter
Sensors in
2-electrode method resistivity sensor (ERF-001 Series) of cell constant 0.01/cm
Measuring rangeResistivityMΩ•cm0.000 to 2.0000.00 to 20.00 (*1)
kΩ•cm0.00 to 20.000.0 to 200.0 (*1)
Temperature0℃ to 100℃ (Display range: −10℃ to 110℃)
ResistivityAs shown in the measuring table.
PerformanceResistivityRepeatabilityWithin ±0.1% of the full scale (response for equivalent input)
LinearityWithin ±0.5% of the full scale (response for equivalent input)
TemperatureRepeatability±0.1℃ (response for equivalent input)
Linearity±0.5℃ (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
Linearity±0.08 mA (output only)
Repeatability±0.02 mA (output only)
Output rangeResistivity: Free setting within a 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 input1
Contact typeNo-voltage "a" contact for open collector
ConditionsON resistance: 40 Ω max.
Open voltage: 1.2 V DC
Short-circuit current: 21 mA max.
Contact functionExternal input for transmission holding.
Applicable temperature
Platinum resistor: 1 kΩ (0℃)
Compensation method 
  • Temperature characteristic of NaCl (reference temperature: 5℃ to 95℃)
  • Arbitrary temperature coefficient input (reference temperature: 5℃ to 95℃; temperature coefficient: +/−3%/℃)
  • No temperature compensation
    One of the three ways of compensation is selectable.
    (In the de-ionized water area, the temperature compensation for pure water is automatically performed in both NaCl and arbitrary temperature coefficient compensation settings.)
Temperature compensation
0℃ to 100℃ (However, the compensation calculation is extended lower than 0℃ or higher than 100℃.)
CalibrationResistivityBased on parameter input of coefficient for the sensor cell constant.
TemperatureComparison to the accurate thermometer
Both deviation and coefficient of RTD are taken into account for calibration.
Other functionUPW standard resistivity inputSelect one from the next.
182.3 kΩ•m (standard), 181.8 kΩ•m, 182.4 kΩ•m,
18.23 MΩ•cm (standard), 18.18 MΩ•cm, or 18.24 MΩ•cm
Clipping functionIf the measured value exceeds the user setting value for clipping, the measured data will be held at the clipping value.
Self-checkElectrode diagnostic errorTemperature sensor short-circuit, temperature sensor disconnection, and out of the temperature measurement range
Meter errorCPU, ADC, and memory errors
−20℃ to 60℃ (without freeze)
humidity range
Relative humidity: 5% to 90% (without condensation)
−25℃ to 65℃
Power supplyRated voltage24 V DC (operating voltage range: 21 V to 32 V DC)
Power consumption0.6W max.
CE markingEMC directive: EN61326-1
RoHS Directive: EN50581
Electostatic dischargeIEC61000-4-2
Electromagnetic field of radiated radio frequencyIEC61000-4-3
Electric fast transient/burstIEC61000-4-4
SurgeIEC61000-4-5 (*3)
Conducted interference induced by radio frequencyIEC61000-4-6
Radiated disturbanceCICPR 11 CLASS A
Noise terminal voltageCISPR 11 CLASS A
FCC RulesPart15 CLASS A
StructureInstallationOutdoor installation type
Installation methodMount on 50 A pole or wall
Protection codeIP65
Case materialAluminum alloy (coated with epoxy-denatured melamine resin)
Material of fittingsSUS304
Material of coverSUS304 stainless steel (coated with epoxy-denatured melamine resin)
Material of display
Display elementReflective monochrome LCD
180 (W)  × 155 (H)  × 115 (D) mm (excluding mounting brackets)
MassMain body: Approx. 2.8 kg; cover and mounting brackets: Approx. 1 kg


  • Note 1  : Without temperature compensation, 0.0-100.0 MΩ•cm(0-1000 kΩ•m) can be displayed.
  • Note 2  : The maximum load resistance that can be connected is decided depending on the powersupply voltage.


Relation between power supply voltage and load resistance

  • 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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