Calibration of thermohygrometers

Hi, I work in a bread factory and I want to know at for nr. 5.4 on IFS - Calibration, adjustment and checking of measuring and monitoring devices, if we use thermohygrometers in daily monitoring we have to calibrate them? and how often? and who does the calibration? can we do it internaly?

Thank you

Hi, I work in a bread factory and I want to know at for nr. 5.4 on IFS - Calibration, adjustment and checking of measuring and monitoring devices, if we use thermohygrometers in daily monitoring we have to calibrate them? and how often? and who does the calibration? can we do it internaly?

Thank you

hi Laura, i think thermohygrometer dont need to calibrate daily, maybe you can calibrate that weekly or monthly. you can calibrate internally if you have one master thermohygrometer that you have calibrate to the institution that have standard certification as a comparison, then you can use the difference of the scale as a corrective value. master thermohygrometer we use to compare must be calibrate minimal once a year...