Portable Dual-Block Model 9009 eliminates need to carry 2 separate temperature sources. Cold block achieves temperatures of -15 to +110°C with accuracy and stability of ±0.2°C. Hot block covers 35-350°C with accuracy of ±0.6°C and ±0.2°C stability. Each block contains 2 dry wells, so calibrations may be performed using external reference thermometer for best accuracy. Instrument is housed in water-resistant case.