In addition to the standard dew point sensor, the Series 4TEV has a hygroscopic polymer capacitance sensor that can be used to measure the water activity of samples containing volatiles. You can switch between sensors using the instrument menu. The capacitance sensor is less accurate (± 0.015 aw) than the dew point sensor (± 0.003 aw).

For samples containing volatiles: 4TEV and AQUALAB TDL

The Series 4TEV is best for customers who occasionally need to measure samples that contain volatile ingredients in low concentrations. If the product itself is volatile (soy sauce, alcohols, flavorings, black tea) or contains a high concentration of volatiles (flavored teas, sauces and seasonings), the laser sensor in the AQUALAB TDL is a better option.


  • Fast: water activity readings in 5 minutes or less
  • Switch easily between volatiles and non-volatiles sensors
  • Volatiles sensor accuracy: ± 0.015 aw
  • Non-volatiles sensor accuracy: ±0.003 aw
  • Verifiable with independent salt standards
  • Repeatable: different users, different locations, same result
  • Portable: the meter weighs just 7 pounds
  • Easy to use: precise measurements with minimal training
  • Secure: offers administrative control over calibration and sample data


Water activity Range: 0.030–1.000 aw
Resolution: 0.0001 aw
Accuracy: ±0.003 (4TE dew point)
±0.015 (4TEV capacitance)
Repeatability: 0.001 aw
Temperature Range: 15-50 °C
Resolution: 0.01 °C
Accuracy: ±0.2 °C
Read time ~5 min
Case dimensions Length: 26.7 cm (10.5 in)
Width: 17.8 cm (7.0 in)
Height: 12.7 cm (5.0 in)
Case material POLYLAC PA-765 (ABS) with fire retardant
Sample cup capacity 14 mL (0.47 fl oz)
Weight 3.1 kg (6.8 lb)
Display 64 × 128 graphical
Operating temperature Minimum: 4 °C
Maximum: 50 °C
Operating environment 0%–90% noncondensing
Sample dish capacity 7.5 mL recommended (15 mL full)
Data communications USB A and RS-232 serial
9,600–115,000 baud
Power 110–220 VAC
50/60 Hz
COMPLIANCE Manufactured under ISO 9001:2015
EM ISO/IEC 17050:2010 (CE Mark)