FM Approved Point Level Probes

Featuring the unique EASY-ON connection system

Description

PRINCO point level probes are as versatile as the PRINCO controllers with which they are used.  Designed to be dependable, rugged, and economical, they serve in a wide variety of applications.

The sensor probes listed in this bulletin are Factory Mutual Approved, explosion-proof for Class I, II, and III, Division I, Groups A, B, C, D, E, F, & G when used with any FM approved PRINCO point level control.

Each probe listed incorporates Princo’s unique NULL-KOTE™ design.  The NULL-KOTE feature incorporates a three-element assembly consisting of a bare sensor rod, guard section, and NPT mounting hub.  All wetted metal parts are type 316 stainless steel.  The elements are insulated from one another with Teflon.

The guard section, in conjunction with the NULL-KOTE circuitry, provides immunity to conductive coating build-up and assures accurate, repeatable operation.

Additionally, each probe incorporates our unique ROLLOCK™ construction.  Featuring rolled seals and welded assembly, this design locks all elements of the probe in position and ensures that no part of the probe can fall into the process or be blown from the mounting.

Application

Point level control is a requirement found in all areas of the process industry.  Such applications may include liquids, slurries, interfaces, powders, and granulars.

In non-conductive liquids or slurries, horizontal installation is recommended.  Vertical installations, depending on the proximity of the ground reference, may require up to six inches of probe immersion before a stable trip point is achieved.  The L854 probe is ideal for vertical installation in non-conductive, low viscosity liquids.

For conductive liquids and slurries or for interface detection, either vertical or horizontal installation is recommended.  Vertical installations will be tip-sensitive.  Probes for powders and granulars should be installed horizontally. 

Installation

A ground reference element is required in most installations.  This usually takes the form of the metal vessel wall.  In other cases, a metal ground pipe, structural element, or ground rod, which extends to a point that is equal to or greater than the lowest point of the sensor may be used.  There must be less than 1 ohm of resistance between the ground reference element and the probe mounting hub or the case ground of the controller.

When mounting a NULL-KOTE point level probe through a nozzle or standpipe, or when mounting in a tank where heavy product build-up is possible on the inside walls or top, the guard element must be long enough to extend at least two inches beyond any such build-up.