Magnetic Inspection Rods

A light, stainless steel hand tool; it detects metal contamination manually in raw material, mixtures or on the production line. It is valuable for quality control in the food and recycling sectors.

The simplest inspection tool

The inspection rod is used to see before measuring the metal contamination in the line. A stainless-bodied magnet rod with a handle is plunged into a heap of raw material, a mixture or a sample; when it is withdrawn, the particles sticking to it are assessed directly by eye.

What it is for

This simple tool gives a quick answer to three questions: is there metal in our line, what size is it and where is it getting in? Plunging the same rod into samples taken at different points is the most practical way to narrow down the source of contamination. For example, if there is metal in a sample taken after the granulator but none before it, the source is clear.

As a quality control record

In the food and recycling sectors periodic inspection is often a requirement of the quality system. Recording the check made with the rod by date, point and finding provides the evidence required at audits.

Its limits

The inspection rod is a diagnostic tool, not protection. To protect the line continuously, a separator suited to the flow type is needed: free-fall separators in lines flowing by gravity, pressure line separators in pressurized lines. In addition, the rod shows only magnetic metals; aluminum and most stainless steels do not stick to it.

Where metal gets into a plastics line and at which point it should be caught is explained in the metal separation guide.

Keeping records

The value of a check made with the inspection rod emerges when records are kept regularly. When the date, sampling point and amount of metal found are recorded, the periods when contamination increased and its source become visible. A one-off check shows only that moment.