Hi AnjaDe! I have a problem with calculating uncertainty. My experiment was to measure the rate of reaction of catalase (% change in O2 against time) and I am struggling to find the uncertainty in time. I've used a Vernier Oxygen Sensor and a Lab Quest, however, I'm not sure how to find the time uncertainty, and I just know that I have to find out the time uncertainty of the device. I've looked up the user manual for the O2 sensor, and found that the Response Time is 90% of final reading in ~12 seconds. Do I find the uncertainty from this value? Do you know a way to do this or how to find it? Thank you so much in advance!