my tank thermometer – will it work…..?

my tank thermometer is a magnetic strip that you stick to the side of the aquarium – will it keep working if i pull it off carefully and re-stick it? it has only been on for a day, so should still have stick on it…
cool thnks i did it, and it seems to read – but my heater is on 26.c and the thermometer is on the opp side of tank (20gallon)- and says only 23.c – is this normal?

Buy a thermometer that is actually touching the water. the tape thermometers are not accurate because they read the temperature of the glass and the the water itself!!

How to Care for Sand Boa Constrictors : Sand Boa Cage Thermometer