sensors are used to monitor the pressure and tempature of a chemical solution sotred in a vat. The circuitry for each sensor produces a high voltage when a specified maximum value is exceeded. An alarm requiring a low voltage input mut be activated when either the pressure or the temperature (or both) is excessive.

What is your question?

Need da truth table for this. I know the answer is NAND gate but, I don't know the reason behind it. Can you giv me why it is NAND?

Sorry, but I can't help with the answer. I was only trying to help the gurus in this area by asking you to clarify what your question was.