Chell has two MM transmitters. They will be labeled transmitter #1 and 2# for this post. I know Chell usually can't get past 5 days of a sensor, and I hate the 2 hour warm up time for Chell. Transmitter #1/ sensor used for 5 days, with some major off readings at the start of this sensor, now just minor off readings. Time left of sensor was less than 10 hours, before sensor ended. I left this running. Transmitter #2 charged New sensor put it (old one is still hooked up and running) Transmitter #2 hooked up, and waited for blinking lights. (of course not turned on) I left this hooked up for at least 3 hours to get nice and wet. I knew Chell was stable as much as can be, I put in the transmitter #2 ID into the pump. Then I went and hit new sensor, and immediatly it asked for a calibration. As soon as we put in Chell's blood sugars, we pulled Transmitter #1 and sensor. Reading from transmitter #2 doing well. I think all together we lost maybe 15 minutes of data not 2+ hours of data. I have had this thought for awhile, but I wanted to think it out first, and then do before I posted this.