Field-installation Type Electric Conductivity Meter (Two-Wire Transmission, For Low-concentration)

HE-300C connects conductivity sensor (ESH/FS Series)  and measures conductivity and temperature in the sample water. It is suitable for monitoring  pure water/boiler water drainage recovery control and  inline measurement of pharmaceutical water conductivity according to USP<645> quality guidelines.

Measurement range

Conductivity: 0 - 2000 μs/cm, 0 -200.0 ms/cm
(TDS conversion 0 - 2000 mg/L)
Temperature: 0 - 100 ℃

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 nameConductivity meter
Sensors in combination2-electrode method conductivity sensor
ESH and FS Series sensor of cell constant 0.01/cm, 0.1/cm, or 1.0/cm
(*Note 1)
Cell constant (/cm)0.01
ConductivityμS/cm0.000 to 2.000
0.00 to 10.00
0.000 to 2.000
0.00 to 20.00
0.0 to 100.0
0.0 to 200.0
0 to 1000
mS/m0.0000 to 0.2000
0.000 to 1.000
0.0000 to 0.2000
0.000 to 2.000
0.00 to 10.00
0.00 to 20.00
0.0 to 100.0
mg/L0.00 to 2.00
0.0 to 10.0
0.00 to 2.00
0.0 to 20.0
0 to 100
0 to 200
0 to 1000
Temperature0 to 100 (display range: −10℃ to 160℃)
/ TDS conversion
As shown in the measuring table.
PerformanceConductivityRepeatabilityWithin ±0.5% of the full scale (response for equivalent input)
Within ±5% of the full scale in the range of 2000 μS/cm or 200 mS/m for FS-01 sensor
LinearityWithin ±0.5% of the full scale (response for equivalent input)
Within ±5% of the full scale in the range of 2000 μS/cm or 200 mS/m for FS-01 sensor
TDS conversionRepeatabilityWithin ±1.5% of full-scale value (response for equivalent input)
LinearityWithin ±1.5% of full-scale value (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 insulation type (two-wire transmission type)
Load resistanceMaximum: 600 Ω. Case of 24 V DC power supply (*Note 3)
LinearityWithin ±0.08 mA (output only)
RepeatabilityWithin ±0.02 mA (output only)
Output rangeConductivity: 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.
Number of input points1
Contact typeNo-voltage a-contact
ConditionsON resistance: 40 Ω max.
Open voltage: 1.2 VDC
Short-circuit current: 21 mA DC max.
Contact functionExternal input for transmission holding.
Temperature elementPlatinum resistor: 1 kΩ (0℃)
Temperature compensation
  • 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℃.)
Temperature calibration1 point calibration comparing to reference thermometer
CalibrationConductivityBased on parameter input of coefficient for the sensor cell constant.
TDS conversionConversion by user-defined coefficient value
(TDS calculation is 0.30 to 1.00 times of sample conductivity by μS/cm.)
Self-checkSensor diagnosis errorTemperature sensor short-circuit, temperature sensor disconnection,
and out of the temperature measurement range
Meter errorCPU error, ADC error, and memory error
Operating temperature range−20℃ to 60℃ (without freeze)
Operating humidity rangeRelative humidity: 5% to 90% (without condensation)
Storage temperature−25℃ to 65℃
Rated voltage24 V DC (operating voltage range: 21 V to 32 V DC) (*Note 3)
Power consumption0.6 W 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
(*Note 2)
Conducted interference induced by radio frequencyIEC61000-4-6
Class A
Radiated disturbanceCICPR 11 CLASS A
Noise terminal voltageCISPR 11 CLASS A
FCC RulesPart15 CLASS A
StructureInstallationOutdoor installation type
Installation method50 Mount on 50 A pole or wall
Protection codeIP65
Case materialAluminum alloy (coated with epoxy-denatured melamine resin)
Material of fittingsSUS304
Material of hoodSUS 304 stainless steel (coated with epoxy-denatured melamine resin)
Material of windowPolycarbonate
Display elementReflective monochrome LCD
External dimensions180 (W) × 155 (H) × 115 (D) mm (excluding mounting brackets)
MassMain body: Approx. 2.8 kg; cover and mounting brackets: Approx. 1 kg


  • Note 1: Only the sanitary sensor (FS-01 series) is applied.
  • Note 2: Conductivity measurement and TDS conversion measurement cannot be selected at the same time.
  • Note 3: The maximum load resistance that can be connected is decided depending on the powersupply voltage.


Relation between power supply voltage and load resistance

Relation between power supply voltage and load resistance

  • Note 4: 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 5: 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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