Adding a tiny C005 timer to a 3V digital caliper was a fun modification. The timer runs on 2-5V, so this would not work in a 1.5V caliper with LR44 battery.

The caliper shown in this video:
https://www.amazon.com/dp/B0CSNNG6P4

Most digital calipers (other than genuine Mitutoyos) are plagued with a short battery life. This is due to a constant standby current draw from the battery. The display goes blank in the "OFF" state but the battery continuous to be used. A cut-off switch would solve the problem. However, for whatever reason, no manufacturer has come up with the simple idea. ...So far.

I decided to use the little CMOS timer C005 as a "switch" and it worked out great!

Some info about C005 timer:
   • An interesting timer IC from Alice110...  
https://westsideelectronics.com/ and add this line /delay-timer-ic/