Zero out at measuring instrument

Thread Starter

Saadi ali

Joined Jun 29, 2023
Hy frnds, i am trying to study electronics trouble shooting, i have gas analyzer wich shows measurements in local display and at remote display through 4 to 20mA signal, problem is that it's zero is totally out, it shows 4% at nil gas detection, but analog signal is ok as 4mA at nill gas detection, i tried my best to set zero by adjusting both zero and span potentios but it stuck at 4%, what might be the problem