dipricol egt guage question

[CFowler]

hello to all. this is my first post. hopefully some of you are using dipricol guages and can help me out . once unpacked the egt read 75 degrees , not zero ,in my house . hooked it up seems to work good 400 degrees idle 7-800on a good launch . let it sit overnight next morn same thing 75-125degrees . maybe it is out of calibration?the tech at genos said not to worry . any help would be apreacheated. thanks in advance .