Model 702A two piece gland probe

These probes are used with Robertshaw RF and microprocessor based ON/OFF or continuous level controls for measuring applications involving liquids or granular materials.

When the probe is used with an ON/OFF (fixed level point) type, it may be installed in the vessel in either a vertical or horizontal position. If, however, the probe is to be used on a continuous level measuring application or on an application with a differential (such as Pump On/Pump Off), then it must be installed into the vessel in a vertical position.

Bent probes are available to allow the active length of the probe to be different from the installation direction. See "Bending Specifications."

When the process is a conductive liquid (such as water or sulfuric acid) and the vessel is non-metallic or non-metallic lined, a probe with a ground wire may be employed to provide a ground path to the liquid (second plate).

The liquid must be clean and free of foreign materials and be no more viscous than water.

The Robertshaw Level Measuring instruments have been designed so that they attach directly to the 1/2" NPT fitting on the top of the probe. Typically, these are either the complete transmitter housing or a conduit outlet box with a coaxial cable to the instrument. The 6-32 threaded fitting in the end of the probe rod accepts either a contact pin or a machine screw as required.

The Model 702A 702A probe is primarily intended for those applications requiring a bent probe and obstacles within the vessel prevent the probe rod from rotating during installation or when a bent probe rod must be oriented after installation. The probe compression plug may be loosened during installation allowing the probe gland to rotate and be tightened while the rod is held stationary. The rod may then be oriented as required and the compression plug tightened. It should be noted that a bent 702A probe cannot withstand a lot of side loading. It is recommended that, whenever possible, a 740A general purpose probe or 741A high gain probe be considered in lieu of a 702A probe.