We have designed multiple temperature sensors. its executed as well too. but we need external power supply or Uninterrupted Power supply for Rpi. I have chosen power bank ..but it works with only one way..which means while charging it doesn't provide output. so please suggest me a proper UPS.
Here's a couple of USB devices that operates in a UPS fashion.
These are just examples for the power bank route, i haven't personally tested the above, but that's the kinda thing you want.
Or if you want to go hardcore, get an entry level server one like this ...
Which i have personally used for servers and they are handy well built things, heavy as hell though. Do the math against your power draw but one of those could last days running a pi.