Environmental & Scientific Instruments Co.
Environmental & Scientific Instruments Co.


Contact Us

Plot – 123, Industrial Area, Phase – II, PANCHKULA, Haryana - 134113, India

Mobile : +91-9216626616

Phone : +91-172-5033251

Fax : +91-172-2591407

Call Us : 08043692865

Digital Conductivity/TDS Meter- 641

EI's Digital Conductivity/TDS Meter Model 641 is an accurate test instruments for measurement of Conductivity and TDS of aqueous solutions. It uses the latest microcontroller technology to measure the Conductivity from 200μS to 1000μS and TDS from 200ppm to 1000ppt in 5 ranges respectively. The appropriate range is automatically selected by the instrument. The Resolution is 0.1μS for Conductivity and 0.1 ppm for TDS in the lowest range. The cell constant is flashed on a digital display and can be adjusted from the front panel. Facility is also provided for automatic measurement of cell constant with a known standard solution. These instruments are ideal for monitoring salt contents in water and soluble salts in soils. They are extremely useful instruments for agriculture and soil analysis lab, swimming pools, fertilizer plants, mineral water plants, petroleum refineries, textile plants etc.


Range : Semi Auto Analyser, Single Beam and double Beam UV/VIS Spectrophotometer, Flame Photometers, Haemoglobin Meter, Digital pH, Meter, Digital Photo Fluorometer, Digital Conductivity Meter, Digital Photo Colorimeter, Turbidity Meter, Auto KF Titrimeter, Digital DO Meter, Digital Conductivity Meter, Digital TDS Meter, Temperature Indicator, Digital Telethermometer, Water & Soil Analysis Kit, Digital Salinity Meter, Digital Colony Counter, Portable pH Meter, Portable Conductivity Meter, Portable TDS Meter, Portable DO Meter, Digital Tablet Disintegration Apparatus, Digital Friability Test Apparatus Tablet Dissolution Test Apparatus, Melting Point Apparatus, Student Microscope, Binocular microscope, Medical Microscope, Co-Axial Microscope.



  • Microcontroller Based
  • Measures Conductivity and TDS
  • Auto Ranging Facility
  • Auto Cell Constant Measurement
  • 3½ Digit Display

Technical Specifications

Parameter Conductivity TDS
Display 3½ Digit Bright Red LED Display
Range Five Ranges
0 - 200 μS/cm
0 - 2 mS/cm
0 - 20 mS/cm
0 - 200 mS/cm
0 - 1000 mS/cm
Five Ranges
0 - 200 ppm
0 - 2 ppm
0 - 20 ppt
0 - 200 ppt
0 - 1000 ppt
Range Selection Automatic
Resolution 0.1 μS/cm in lowest range 0.1 ppm in lowest range
Accuracy ±0.5 % FS ± 1Digit ±0.5 % FS ± 1Digit
Manual - 0 to 50°C
Cell Constant Adjustable on Digital Display
Auto Cell Constant
Available using any standard solution
Measuring Cell Platinum DIP Type
Dimensions 270 x 202 x 80 mm (l x b x h approx.)
Weigh 0.8 Kg approx.
Accessories Conductivity/TDS Cell , Operation Manual, Cell Stand, Dust Cover,
12V Adapter
Power 12V DC using Adapter 110 to 250V AC,50 Hz