Iam-T1 calibration problem after battery change

I was using this device for past 3 months. Everything was going fine.

Then the battery went low. I changed the battery. And after I changed it. The calibration went out of range. It was showing 198 as normal.

Then I pressed auto calibiration, then factory reset, then auto and so on. So that it reaches right level. But everytime I clicked factory reset. The value went down and down and down. And now its placed outside in open area. The reading is 114. The more times I press factory calibration button, further down it goes. Now I have kept it in the open with auto calibiration on. 27th October, 2026 9:30 AM IST.

At 10:00 am I said 169.

Now at 9:00pm it says. 111. Which is not right

It should show somewhere near 460 as it used to.

w 169.