HD-200FL (Four-Wire Analyzer)




Combined sensor

5700 A optical DO sensor

Combined probe


Measurement range

Dissolved oxygen concentration:
 0 mg/L to 20 mg/L (Display range: 0 mg/L to 22 mg/L)
 Display resolution: 0.01 mg/L
Saturation ratio:
 0% to 200% (Display range: 0% to 200%)
 Display resolution: 0.1%
 0°C to 50°C (Display range: -10°C to 110°C)
 Display resolution: 0.1°C

Transmission output

Number of output: 2
(The negative terminals for transmission outputs are internally connected at the same electric potential)
Output type: 4 mA to 20 mA DC: input/output isolated type
Load resistance: Maximum: 900 Ω

Contact output

Number of output: 3
Output type: No-voltage contact output
Contact type: Relay contact; SPDT (1c)
Output capacity: 250 V AC 3 A, 30 V DC 3 A (resistance load)

Cleaning output

Number of output: 1
Output type: AC power control output ( Applied power supply voltage)
Contact type: Relay contact; SPST (1a)
Output contact capacity: 250 V AC 3 A, 30 V DC 3 A (resistance load)
External instrument: Solenoid valve for cleaning control

Contact input

Number of input: 1
Contact type: No-voltage "a" contact for open collector

Communication function

Communication type: RS-485
Signal type:
 2 wire system, isolated from the input circuit
 Not isolated from transmission circuit

Temperature compensation

Temperature compensation range: 0°C to 50°C
Temperature calibration: 1 point calibration comparing to reference thermometer


Calibration method:
 ・Span calibration in the air
 ・Zero: Sodium sulfite solution
 ・Span: Air or DO saturated water


Calibration error
Electrode diagnostic error
Meter error

Operating temperature range

-20°C to 55°C (without freeze)

Power supply

Power supply voltage range: 90 V to 264 V AC 50/60 Hz
Power consumption: 20 VA(max)

Compatible standards

CE marking, FCC Rules


Installation: Outdoor installation type
Installation method: Mounted on 50A pole or wall
Protection code: IP65 IEC60529, JIS C0920
Case material: Aluminum alloy (coated with epoxy-denatured melamine resin)

External dimensions

180 (W) x 155 (H) x 115 (D) mm (excluding the fittings)


Main body: Approx. 3.5 kg; cover and fittings: Approx. 1 kg

Note 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 dissolved oxygen value ± 0.4 mg/L.

Note 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.

Note 3:
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.


Product name

Optical DO probe



Measuring method

Optical sensor

Measurement range

Dissolved oxygen: concentration 0 mg/L to 20 mg/L
Saturation range: 0% to 200%
Temperature: 0°C to 50°C



Measurement condition

Sample pressure: 0 MPa to 1.0 MPa

Operating temperature range

0°C to 50°C

External dimensions

Φ43×L230 mm


Approx. 3.0 kg


Product name

Optical DO sensor






Approx. 1.5 kg (with 10 m cable)


Embeded memory, Automatic data translat