Determining LTM-2 Probe Length

Determining LTM-2 probe length is fairly straight forward. Required length is the distance between the bottom of the head elevation to the expected lowest slurry measurement level. LTM probes are supplied in lengths ranging from 500 mm minimum to a maximum 3000 mm in 100 mm length increments. Separate probe length determination descriptions for flotation cells/mixer tanks and sumps are provided as follows.

FLOTATION CELLS / TANKS

The first decision is determining where the probe bracket will be attached to the flotation cell structure. Zeroday supplied probe brackets have an adjustable connector that allows variable vertical positioning so the probe height relative to the bracket attachment point can be set. Generally best practice is positioning the connection point as high as possible on the bracket pipe to minimize probe length, although assess to the probe head will require in some cases elevating the probe relative to the connection point elevation.

The probe bracket must be attached to the cell superstructure to ensure electrical continuity. Attachment by bolting or welding are acceptable as long as the contact is electrically conductive.

The probe must be deep enough in the cell to measure expected lowest slurry level. The must add an additional 70 mm to account for the non-measuring bottom fitting that holds the bracket in place. DO NOT position the probe in the high turbulence impeller zone as this can cause excessive probe-bracket wear.

The total probe length required is the vertical distance between the bottom of head to expected lowest slurry level depth + 70 mm.

SUMP

Locating the probe head above the sump wall height is recommended. Even though the probe head is IP69K rated which means the head is ‘dunk proof’, for practical maintenance and probe life reasons, locate the head so will not be submersed in slurry continuously.

The probe must be attached to the sump as described in the foregoing flotation cell-mixing tank section. There must be good electrical contact between the probe bracket and the sump. This will establish the height of the head and the probe length measurement will be at the bottom of the head.

For full sump level measurement range, the probe should extend into the sump just above the pump discharge pipe height. Unlike flotation cells, the measured depth will be at the bottom of the bracket. This establishes the probe length required. Setting the probe depth within the pump intake flowstream poses excessive probe wear possibility.

Categories: LTM-2 Probe, Sumps