What is a pH sensor vs. a pH meter?

I want to know the details about ph meters.
Is there any difference is there between ph meter and ph sensor.
Is ph sensor can be placed on line in an industry?
Please give me the maximum possible details about this topic

Please describe your situation, Poornima, rather than asking the readers to write an individualized tutorial textbook with "maximum possible details" for you. It's an unrealistic task to assign to a stranger on an internet forum.

The meaning of 'pH sensor' is context dependent. In some contexts it means just the sensing head or probe that transmits the chemical potential to a remote pH instrument, whether that be a portable lab instrument or an on-line analyzer. Some manufacturers encapsulate a preamplifier in their "sensor" so it transmits a 4-20 mA signal rather than just a chemical probe potential. In some contexts "sensor" can mean the entire pH sensing instrument, not just the head. For example, you might read "place the pH sensor in a beaker of buffer solution" or you might read "the pH sensor controls the addition of neutralizing reagent".

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey