Thermo-Hygrometer, -4 to 140°F (-20 to 60°C), 0-100%RH with NIST Calibration Certificate, Reed Instruments, Mfr#: R6001-NIST$429.99+
Humidity Calibration Standard, 33%. For use with REED R6001, R6200, SD-3007, R9900 and 8706., Reed Instruments, Mfr#: R9933$67.94+