It is probably not the app specifically, but wakelocks and/or alarms, so you will not see them directly related to the app in these statistics.
Wakelocks are a tool apps or the OS can use to keep your device from deep sleeping. I have used 2 bluetooth devices lately that cause excessive battery drain and in both cases I noticed huge amounts of wakelocks, so my device was sleeping only maybe 1/4 of the time that the screen was off. I want my phone to be sleeping as much as possible (without sacrificing functions I need)!
Alarms are a way that an app can wake up your device if it's sleeping, and it's likely that your app would wake up the phone periodically to take a measurement. If it's only every 5 minutes, that would not be significant, but sometimes you will see an app with hundreds of wakeups per hour.
A good tool to see alarms and wakelocks is better battery stats. There is also a non-root version of wakelock detector. In either case you need to use an adb command to give them access to your battery stats, so digging into this level of battery usage is not going to be for everyone, but it was one of the first things I learned about when I got into android because I couldn't understand why my battery didn't last longer on standby.
The other unfortunate thing is there is not much you can do about this nowadays. Back in the days when I was rooted and using xposed, there was all kinds of work being done to "tame" excessive wakelocks and alarms.