Final answer:
A vacuum gauge connected to a chamber reads the gauge pressure in the chamber.
A negative reading indicates pressure below atmospheric pressure, while a positive reading indicates pressure above atmospheric pressure.
Step-by-step explanation:
A vacuum gauge connected to a chamber reads the gauge pressure in the chamber. Gauge pressure is the pressure relative to atmospheric pressure.
When the gauge reads a negative value, it means that the pressure in the chamber is less than atmospheric pressure.
Conversely, when the gauge reads a positive value, it means that the pressure in the chamber is greater than atmospheric pressure.