Moisture Analyzer – HydroTracer

Tinius Olsen launches a moisture analyzer that will interest all manufacturers with moisture apprehensions. This new tester is less expensive, just as fast to produce a result, and as accurate as comparable heat and weigh or microwave method-based testers. The patented technique of the HydroTracer establishes the absolute water content where the mass of the water is measured inside the reactor.

Similarly, operation is simple. The sample is weighed and placed into the HydroTracer’s sample tray, which is then positioned in the tester’s heating chamber. The heater warms the sample to a temperature selected by the operator, and water inside the sample evaporates. The heating chamber is joined with the cooled upper reactor chamber of the HydroTracer – this is where the calcium hydride reagent is located. The volatile water rises to the upper reactor chamber and when the humid air flows over the reagent, the gaseous water reacts with calcium hydride according to the following equation:

CaH2 + 2H2 O → Ca(OH)2 + 2H2

The cooled, dry air returns to the lower heating chamber and the process carries on. The circulation of air through the HydroTracer is aided by natural convection, which is stimulated by the unique design of the HydroTracer; even hygroscopic materials are totally dried with the analyzer. The final concentration of hydrogen in the reactor is comparative to the water content of the sample before the measurement. The entire operation process is regulated by PC-based software and the results calculated for the operator.

The ambient air also adds water to the reactor atmosphere; to attain accurate results the ambient air humidity and density has to be defined and ‘removed from the equation’. Integrated sensors in the reactor perform this task. Thermal conductivity sensors measure the concentration of hydrogen.

Chemical Reactions and the Reagent

Calcium hydride reacts with water to develop calcium hydroxide (also known as hydrated lime, or agricultural hydrate), which is a weak base and relatively harmless; it also does not require any special disposal methods. The small amount of reagent required for the test means that the amount of hydrogen created is small and subsequently does not result in any operational issues.

HydroTracer Principle of Operation

1. Sample in a removable heating tray
2. Hot humid gas rises into the reactor chamber
3. Reagent absorbs water vapor and discharges hydrogen gas
4. Sensors measure hydrogen gas concentration
5. Cooled, dry gas descends and can absorb more water vapor


Sample weight 0.01-200 g , depending on sample density
Reproducibility ±0.05 mg H2O (1 mg water content) up to ±0.5 mg H2O (20 mg water content)
Display via PC Absolute water content of sample in x.xxmg
Relative water content in x.xxxx% and xppm
Additionally ambient air temperature, relative humidity and pressure
Measuring range 0.2-30 mg H2O
Test temperatures 50-210 °C in 1 °C steps
Reagent CaH2 powder-form approx. 0.1 g each measurement
Ambient air temperature In °C in 0.1 °C steps
Ambient air pressure 700-1100 mbar in 0.1 mbar steps
Relative air humidity 0-100% in 0.1% steps
Power supply 115 VAC, 50/60 Hz, 2.8 A or 230 VAC, 50 Hz, 1.6 A
Weight 4.9 kg
Dimensions 285 x 170 x 250 mm (HxWxD)
Interface Bi-directional RS232 interface
Required PC Windows® 98, ME, 2000, NT, XP; Pentium® 233 or equivalent; 64 MB RAM minimum, 128 MB recommended; serial interface RS232

Common Applications

  • Plastics –PA 6, PA 6.6, PA 12, PAI, PAA, TPE, PBT, PC, PE, PE Talcum, ABS, PETa, PETc, POM, PP, PS, PS expanded, PMMA, PEI, PVC
  • Sand
  • Anorganic salts
  • Calcium carbonate
  • Carbon black
  • Caprolactam

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