Robertshaw Capacitance Level Probes
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.
Model 736B Teflon Faced Flange Probe
The Model 736B probe is designed as both a general duty and a heavy duty probe - each with a Teflon faced flange. Various flange sizes and pressure ratings are standard options that are readily available. Flanges are available in either carbon steel or 316 stainless steel. Each gland is welded to the flange selected prior to assembly of the probe. The general duty probe utilizes a 7/32" stainless steel rod with 3/8" O.D. Teflon insulation. The heavy duty probe utilizes a 15/32" stainless steel rod with 3/4" O.D. Teflon insulation. Each probe is of rigid type construction. Other features available on the Robertshaw Model 736B probe are: • Factory bent probes for special uses. • Ground wire probes for use where a ground to the liquid product is hard to obtain. • Probes with a Teflon insulated sheath which makes the sheathed portion of the probe inactive