Aastrid international supplies a range of hand held instruments for temperature and humidity measurement from rotronic. These instruments are available with a]integrated probe- model a1 for measuring relative humidity and temperature in air; model m1 to measure equilibrium moisture content and temperature in powders, granules and model s1 to measure humidity in paper stack; b] separate probe- model a2 for humidity and temperature measurement with analogue output and model am3 to measure relative humidity and dewpoint with rs 232 interface c] model bt rs1 benchtop instrument for one probe for humidity measurement d] model mc 50, model mc 100s non destructive determination of moisture content in building material.