Total Nitrogen (TN) Automatic Analyzer



The TN-520 total nitrogen automatic analyzer rapidly and accurately performs automatic analysis of total nitrogen content in plant discharge and rivers, both online and offline.
The TN-520, based on the track record of the TN-510, also offers built-in dilution and stream switching functions in a compact form.
It requires no test reagents, and the sealed combustion system enables it to measure seawater samples. It requires no waste fluid treatment, making maintenance and management easy.


  • Japan’s Industrial Standardization Act-compliant measurement method
  • Can be used to perform measurements of seawater samples
  • Low-temperature sealed combustion and automatic washing function enable stable long-term measurement of seawater samples
  • Built-in dilution function (optional) 2–20x
  • Up to a maximum of six streams can be measured using the stream switching function (optional)
  • Can handle all types of sample water using various pre-treatment units available as options
  • An offline measurement function is equipped standard


  • River, lake and marsh, sea area, and plant discharge water quality measurement
  • Drainage treatment equipment operation management, experimentation, and evaluation
  • Automatic measurement device for total water quality emissions regulation compliance

Principle of Measurement

The supplied sample is measured in the injection section, and then a fixed amount of the sample is injected into the combustion chamber while still sealed, and the nitrogen content of the measurement sample is completely oxidized.
The generated gas is sent to the infrared analyzer, an electrical signal corresponding to the concentration of nitrogen monoxide is generated and then converted into a linear signal to determine the total nitrogen concentration value.

TN-520 specifications

Measurement range 0–2/20,0–20/200mgN/l
Dilution function 2–20x*1
Stream switching function 2–6 streams*2
Measurement cycle 5–99 min 59 sec
Measurement method Total nitrogen measurement: Automatic intermittent sealed combustion infrared analysis
Calibration method Span calibration: Manual or automatic (optional)
Zero calibration: Manual (with auto zero function)
Conversion function TN value converted into TRANS value and displayed
Washing Automatic washing of injection tube and combustion section; Alternate injection of sample and washing liquid (Washing liquid contained in the unit)
Range setting Manual switching, auto range
Type Standalone console, with casters
Dimensions 602W×500D×1570Hmm
Weight Approx. 120 kg
Standard liquid Aqueous ammonium sulfate solution
Repeatability Within ±3% of full scale
Zero stability Within ±3% of full scale/day
Span stability Within ±3% of full scale/day
Ambient temperature change Within ±3% of full scale/5°C
Measurement value output External output: DC 4–20 mA
RS232C (option)
Range ID signal non-voltage contact: AC 125 V, 1 A
Error alarm indication LED display, Closed contact output in case of error (AC 125 V, 1 A)
Alarms Heater temperature control
Measurement value upper/lower limits
Out of carrier gas (option)
No sample (option)
Out of dilution water (option)
Out of washing water (option)
Sample conditions Online measurement: 0.02–0.1 MPa, 0.1MPa 500 ml/min or higher
Offline measurement: Normal pressure, 200–500 mL/3 measurements
Reagents/Utilities Cleaning fluid: Distilled water
Carrier gas: Refined air Pressure 0.3 MPa, Consumption 43 Nm3/month
Power AC 100 V±10 V 50/60 Hz Approx. 450VA
Set up conditions Indoors
3–40°C during operation (temperature gradient of 5°C/hour or less)
45–85% RH (with no condensation)


  • Tokyo office: +81-3-3241-8461

    Shiga office: +81-77-544-6224

Technological Field
Technology >> Measurement & analysis > Water Quality Analyzers
Industry Sector
Industry sector >> Home appliances & electronics equipment > Home Appliances & Electronic Equipment Sensors