Reed R9975 75% Humidity Standard for R6001/sd-3007/8706/r6200/r9900/r9905/r6050sd

75% humidity calibration standard for verifying and calibrating the same family of REED humidity meters (R6001, SD-3007, 8706, R6200, R9900, R9905, R6050SD). Also rated to roughly +/-1% accuracy at 77...