Starting at $4,135.00
  • Not in stock. Usually ships in 1-2 weeks


  • Probe connections: 4 x HC2 station probe or HC2 insertion probe
  • Parameters shown: Aw, % RH, °C, °F
  • Calculated parameters:
    • Dew point (Dp) above and below freezing
    • Frost point (Fp) below freezing and dew point above freezing
    • Wet bulb temperature (Tw)
    • Enthalpy (H)
    • Vapor concentration (Dv)
    • Specific humidity (Q)
    • Mixing ratio by weight (R)
    • Vapor concentration at saturation (Dvs)
    • Vapor partial pressure (E)
    • Vapor saturation pressure (Ew)
  • Memory: 4 x 500 Aw values
  • Interfaces: Ethernet and USB
  • Power supply: 8 to 16 VDC with AC adapter
  • Display: 3-line alphanumeric LCD with trend indicators
  • Software included

The Rotronic HygroLab C1 Water Activity Indicator is a multifunction bench-top indicator that can read simultaneously up to 4 HygroClip 2 digital humidity-temperature probes. The HygroLab C1 is primarily designed for measuring the water activity (Aw) of foods, pharmaceuticals and cosmetics. The HygroLab C1 can also be used in other laboratory applications that require measuring humidity and temperature.

The measurement of water activity is a key parameter in the quality control of moisture-sensitive products or materials. Water activity is a measure of the water vapor pressure generated by the free or non-chemically bound water in foods and other products. The bound water and moisture content cannot be measured with this method. The free water in a product influences its microbiological, chemical and enzymatic stability. This is especially important in the case of perishable products such as foodstuffs, grain, and seeds as well as in many products in the pharmaceutical and cosmetic industries. If there is too much free water available, the products spoil, and if there is too little water available, other product properties can be influenced negatively. The measurement of water activity also provides useful information on properties such as the cohesion, storage life, agglomeration or pour-ability of powders, tablet stability, and the adherence of coatings.

The HygroLab C1 measures water activity (range: 0.00 to 1.00 Aw), relative humidity and temperature. These measurements allow a number of parameters to be calculated. Four probe connections allow up to four separate samples to be tested simultaneously. Up to 500 records can be captured per probe and each record is stamped for date and time. Data viewing can be done from the keypad and the data can be saved to a PC using the Rotronic HW4 software. Both USB and Ethernet interfaces are included. The HygroLab C1 includes an AwQuick option which provides accurate Aw measurements of most products in about 5 minutes.

The Rotronic HygroLab C1 is available as the indicator only or in a kit which includes:

  • HygroLab C1 bench-top meter
  • AC adapter (115 VAC / 9 VDC)
  • HC2-AW probe for the measurement of product samples
  • WP40 sample holder with depth reduction insert
  • PS14: pack of 100 disposable sample cups (14mm deep)
  • PS40: pack of 100 disposable sample cups (40mm deep)
  • 1 box each: EA00 (0 %RH), EA10 (10 %RH), EA35 (35 %RH), EA80 (80%RH) and EA95 (95%RH) humidity calibration standards
  • HW4 software CDROM
  • 1.8m USB cable for connection of a PC