VEGA VEGACAL 66 PTFE Insulated Capacitive Cable Electrode

A fully insulated cable electrode for non-abrasive liquids and solids

The VEGACAL 66 is a capacitive level sensor for non-abrasive liquids and bulk solids whose cable electrode is fully PTFE insulated, with a stainless-steel gravity weight at the end. Because the insulation covers the whole wetted length, the sensor can be used in conductive products where an uninsulated probe would short, and VEGA lists a measuring range up to 32 m (105 ft) with mounting that VEGA calls simple, offering savings in installation and setup. The sheet notes an optional SIL2 qualification for the two-wire version.

Technical specifications

Design points for a fully insulated cable

The PTFE coat makes the 66 the cable electrode to specify for chemically aggressive liquids and for solids that would abrade a bare surface, though VEGA restricts it to non-abrasive media. The ratings are lower than the partly insulated 65 (40 bar and 150 °C instead of 64 bar and 200 °C), so check the vessel against these limits first. As with every VEGACAL, the sensor needs a grounded connection to a metal vessel, and the cable end should be kept clear of walls; a gravity weight keeps it taut in a liquid. VEGA describes mounting and setup of this sensor as simple, with adjustment carried out through the optional display and adjustment module or PACTware with the matching DTM, and a gravity weight at the cable end keeps the probe straight in the vessel.

Ordering information

Send us probe length, process fitting (thread or flange), medium conductivity, output signal and housing material. The sheet shown is the Profibus PA edition, and the two-wire HART, Foundation Fieldbus and signal-conditioner versions follow the same probe data. Approvals and ship classifications are printed in VEGA’s approval documents and must be confirmed for the exact configuration. For cleaning-in-place or steam-out cycles, confirm that the temperature excursion stays within the stated 150 °C limit, and ask the manufacturer about seals and the process connection before the vessel is released to production.

Installing the cable electrode in the vessel

Choose a nozzle position away from the inlet stream so the falling product does not strike the PTFE cable or swing the gravity weight. Keep a clear distance between the cable and the vessel wall, agitators, ladders and internal pipes along the full length, allowing for the way the cable can move when the level changes. Handle the cable with care during installation: a cut, kink or crush in the insulation exposes the conductor and spoils the measurement in a conductive medium, so do not drag it over sharp nozzle edges or step on it while lowering it in. Make sure the process fitting gives a reliable electrical connection to the metal vessel, as the measuring principle depends on it, and seal the cable gland so moisture cannot enter the housing.

Setting up the measurement

Adjustment is usually done with two reference points, empty and full, or with values taken at two known levels if the vessel cannot be emptied. Enter them through the display and adjustment module or PACTware with the DTM, then check the 4 to 20 mA or fieldbus value against a dip or sight-glass reading at several levels. Note any change in product, since a different dielectric or conductivity can affect the reading and may call for a new adjustment.

Plant conditions in Oman and the GCC

Many VEGACAL 66 applications in the region are outdoor tanks at water treatment, chemical and oil and gas sites, where the housing sits in full sun. The ambient limit printed above is well suited to most sites, but a dark housing on a tank roof in summer gets hot, so a sun shade is worth considering and the housing lid should be kept closed and tightened. Windblown dust can find its way into an open housing during maintenance, so open it only when needed and in calm conditions. On coastal plants, check housing material and cable glands against salt-laden air, and in humid weather make sure condensation inside the housing cannot form by keeping seals intact and unused entries plugged.

Maintenance points

The fully insulated design means there is little to wear in non-abrasive service, but inspections are still useful at planned shutdowns. Check the cable for build-up, swelling or damage to the PTFE, and confirm that the gravity weight still hangs freely and has not become fouled in sediment. Look at the housing seals and the cable entry for moisture. If the reading drifts, compare it with a manual level measurement before changing the adjustment, as build-up on the cable can change the signal. Record the adjustment values so the sensor can be restored quickly after electronics service.

Documents and quotation

The official VEGA VEGACAL 66 (Profibus PA) specification sheet (34619-EN, version 160112) is attached to this page for download and covers the technical data, dimensions and wiring summarised above.

RFQs are welcome with the tag number, medium, process conditions and electrical requirements. Seven Star LLC is an independent supplier based in Muscat and will answer with a quotation; compare alternatives in our level instrumentation section. Ordering details such as configuration, approvals and connection should be confirmed with the manufacturer before purchase.