A glass tube, or a glass faced section of a process line, used for sighting liquid levels or taking manometer readings.
The gauge glass and its fittings for attachment.
A window into the A/C system. Installed in the liquid line or on the receiver drier, they are used to check refrigerant charge and flow. Newer systems using R-134a refrigerants rarely have a sight glass.
a glass tube used to indicate the liquid condition and level in pipes, tanks, bearings, and similar equipment
a window in the liquid line or in the top of the drier used to observe the liquid refrigerant flow.
A window, usually located in the top of the receiver-dryer for observing the refrigerant during diagnosis. Many A/C systems do not have this device.
A sight glass or water gauge is a transparent tube through which the operator of a tank or boiler can observe the level of liquid contained within.