The With the smallest size, the widest range and the highest performance, the Crystal 30 series puts a zone 1 hazardous area certified calibration tool box in the palm of your hand. The intrinsically safe IS31 pressure calibrator is light and compact enough to carry in your shirt pocket. The IS31's internal pressure sensor provides a high 0.05% of reading accuracy, bringing laboratory quality precision to equipment calibrations out in the field. Crystal's perfectly elastic, crystalline sensors never deform and always return to their original shape even after overpressure. Every IS31 comes with an  ISO 17025 Accredited Calibration Certificate, NIST Traceable calibration report and is temperature compensated from 0 to 50°C to guarantee reliably accurate pressure and mA readings across a wide range of conditions.