Online BOD Water Analyzer

Vasthi Instruments are global leaders in manufacturing of Online BOD Water Analyzer and have been supplying instruments to customers worldwide, Our multidisciplinary team of scientists, physicians, engineers, and regulatory consultants with decades of global experience brings you the quintessential mechanism that provides complete safety accuracy and durability. Vasthi Instruments was formed with visionary thinking and innovative ideas resulting in innovative products and solutions. We enhance our product quality by the continuous process of research and development. We have WIDE range of models to suite various site conditions and processes.

Water Analyzer-VEMS-4000


Online BOD Water Analyzer VEMS-4000 is a new type of automatic on-line analyzer for measuring bio-chemical oxygen demand (BOD) of sewage. The Online BOD Water Analyzer uses the latest photoelectric measurement, high temperature and high pressure digestion, digestion and color integration technology, with measurement accuracy, low detection limit, high reliability, strong adaptability and so on. It is in line with national ring Protection Agency released chromium standard test method to obtain a measurement certificate relevant state departments. Reagent used by the instrument can by relevant national standard quasi-self-preparation.

Online BOD Water Analyzer can be widely used in water pollution detection / industrial production process water / industrial and municipal waste water treatment and other fields.


  • MODEL NO:VEMS-4000
  • It Requires no reagents, so it can save operating costs and will cause no secondary pollution .
  • The Response is quick (about 2 seconds ). It is suitable for the occasion where high real time performance is required , such as industrial process analysis .
  • Free from the interference of chloride ion .
  • It Adopts full-spectrum measurement and chemo metric algorithm analysis ,Which in comparison with the simple dual wave length background subtraction technology, can measure more parameters and is less likely to be influenced by the compositional change of waste water.
  • All Components are independently researched and developed
  • It adopts pulse blowing method to clean the pollutants on the two window surfaces. The Instrument probe in the water measures organics in the water by means of xenon lamp . The calculation of the spectrum obtained after each measurement will produce a measured value, which will be transmitted to the control box and displayed.
  • Optical Fiber on the main Interface . One measurement only takes several dozens of seconds . Mean While ,in the interval of measurement , the instrument will be automatically cleaned to prevent contaminants from being deposited on the surface of the lens .



Measuring Parameters

Measuring Rang As Customer required
Method Uv/Visible differential optical absorption spectroscopy, wavelength range   200-800nm
Power 230V  AC, 30w
Linearity 2%F.S.
Zero Gravity <1%F.S.
Range (COD) 0~50~200mg/l,greater range can be customized
Interval The shortest 60 seconds, the cycle can be set
Probes Depth <10m
Optical Path Can be adjusted according to the site condition
Working Temp 5°C~45°C
Enclosure Rating Ip65(secondary instrument)
Auto -Cleaning Auto-cleaning
Interface RS232/RS485(Baud rate can be set),2×4-20ma output
Probe Size 60*380.5mm
Probe Weight 5kg
Interace digital Ethernet (TCP/IP),RS-232 or RS-485 (Modbus RTU)
Power Supply 12-24VDC (±10%)
Output Data
Power Consumption Power Consumption
Environmental Conditions
Sample Temperature +2…+40°C
Ambient Temperature +2…+40°C
Inflow velocity 0.1-10m/s
Performance Characteristics
Maintence effort Typically <0.5h/month
Calibration/maintenance interval 24 months
System compatibility Modbus RTU
Guarantee 1 year (EU:2year)
Max. pressure with sub Conn 30 bar
Max. Pressure with fixed cable 3 bar
Max .pressure in flow cell 1 ber,2-4 L/min
Protection type IP 68
Structural design
Housing material Stainless steel (1.4571/1.4404)or titanium(3.7035)
Weight Stainless steel ~3kg (with 10mm path)
Weight titanium ~2kg (with 10mm path)