I am using a MPXH6300 to monitor pressure inside a rigid hermetic container, I am also monitoring temperature and RH. There is some molecular sieve desiccant in the container. The final test step for the container is a week stability in a temperature controlled chamber.
After the first few hours the monitored temperature stabilises within the control limits of the chamber and pressure can be seen to change as expected with temperature and the RH slowly drops, starting at around 20% and ending at well below 10% by the end of the week.
Over the week the monitored background pressure is seen to rise, seemingly tracking the fall in RH, attached plot. Since other possible variables are stable (supply, ADC) my hypothesis is that the gel coat is drying out and slightly changing the response of the sensor, is this reasonable or is there another explanation?