Nutrients Analyzer
Nitrate Meter

SMR21 series

Nitrate Analyzer

Nitrate Analyzer is connected directly via RS485 communication interface, providing simple, reliable, cost-saving process data with remote monitoring, calibration, configuration and diagnostics capabilities. Nitrate Meter housing in a robust IP68 proof enclosure, 1500 N tensile strength Kevlar reinforced cable, up to 1.2 km digital data transmission, the NO3-N analyzer and NO3-N Meter is ideally used in water/wastewater industry.
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  • All-in-One Compact Housing, Built-in Transmitter and Sensors
  • Robust IP68 Water Submersible Protection
  • Plug & Play, On- line Realtime Measurement
  • Ultra Low Power Consumption, Ideal for Outdoor Applications
  • 1500 N Tensile Strength Kevlar Reinforced Cable
  • Surge Protection for Power and RS485 Communication
  • RS485 Digital Communication, Minimize Cabling and Engineering Cost
  • Standard Modbus RTU Protocol, Direct Connected with PLC, HMI
  • Long Term Stable Electrodes, without the Need of Frequent Calibration
  • Metal Membrane of Electrode to Prevent Scratch
  • Electrode is over 12 Months Long Period of Life
  • Auto Cleaning Wiper, Less Maintenance
  • Onboard Memory Allowing Users Easily Calibrate and Configure Sensor at Lab and Distribute to Various Fields Sites
  • Software Tool for Data Monitoring, Calibration, Configuration and Diagnosis
Drinking water, water treatment, wastewater, fishery
  • Output Signal: RS485 (Modbus RTU protocol), 19,200 bps, 8 data bits, no parity, 1 stop bit; 4~20 mA
  • Data Resolution: 16 bits (0.001% FS)
  • Surge Protection: 4000 V DC
  • Power:5~12 V DC, 20 mA(SMR21-1); 60 mA(SMR21-2)
  • Protection: polarity, overload, short circuit
  • Safety: CE, FCC
Measurement Method
The ion selective electrode continuous measurement of nitrate is carried out with specific membrane that is selective of nitrate. That membrane creates charge seperation between the water surrounded electrode and internal filling solution. The charge is measured as a voltage that changes the concentration in the water adjacent the membrane. Compared with the traditional colorimetric method, there are many advantages such as fast response time, more accurate, easier and no reagents used.

SMR21 Nitrate (NO3-N) Analyzer 
Type Ion selective electrode
Measurement range 0~2,000 mg/L
Accuracy ±5% measured value ±0.5 mg/L
Resolution 0.01 mg/L
Repeatability ±3% measured value ±0.5 mg/L
Operation pH pH 4~11
Operating pressure Max. 0.2 Kgf/cm2
Operating Temperature 0 ~ 40 °C
Process flow rate 0.1~10 m/s
Response time 2 min (90%)
Protection IP68
Sensor NTC 10 K
Measurement range 0~40 °C
Accuracy ±0.5 °CC
Resolution 0.01 °C
Repeatability 0.1 °C
Measurement range 0~1,000 mg/L
Accuracy ±5% measured valie ±0.5 mg/L
Resolution 0.01 °C
Repeatability ±3% measured valie ±0.5 mg/L
Process M26 x 1.5
Housing POM
Dimension Φ 47 x 279 mm
Weight Nitrate analyzer: approx. 1.5 Kg;
Nitrate and chloride analyzer: approx. 1.8 Kg;
cable: 80 g/m
Standard cable length is 3 m, customized length is available upon request