These straight talking gauges might float your boat

So, you're planning something more sophisticated than a dip stick to take tank measurements. But no-one told you there were so many types of gauge / sensor. How do you compare them? Which do you choose?

Perhaps you'd prefer a recognisable design where you can see how it works?

Magnetostrictive gauges

Magnetostrictive gauges are one of the oldest and most versatile gauges in the industry. The comprise an instrument head at the top, a long metal rod (waveguide), and a floating magnet that slides up and down the rod. This float provides the height; as with all gauges you'll need a strapping table from the tank manufacturer to convert from mm to litres. This strapping table is easily integrated into the HyDip system so that your on screen readings are presented as a volume automatically.

Ideally suited for low height liquid tanks magnetostrictive instruments are very resistant to wear. Unlike radar and ultrasonic sensors, they are not sensitive to false readings from internal tank reinforcements like struts or ridges, or other obstacles like ladders. Nor are they sensitive to the dielectric properties of the liquid, as is the case with radar sensors which see right through diesel.

Magnetostrictive gauges are available for many applications including diesel and water, and EX-rated instruments are available for use in explosive applications.

Take care when choosing
When choosing a magnetostrictive gauge, the float density must be chosen to suit the liquid, as it wants to be heavy enough to drop with the liquid level but obviously light enough to actually float. Also the rod length must match the height of the tank, which can make delivery a problem for longer rods, and can make installation difficult if the tank is under a roof, unless you can find one that uses a cable instead of a rod.

Looking after your gauge
The main operational difficulties with magnetostrictive gauges are that they can occasionally stick and need cleaning. Loosening the float may be a minor problem, however getting rid of any build-up caused by the liquid may require removing the rod from the tank.

Connecting to HyDip

One thing to remember, however, is that whichever sensor you've installed it's as easy as wiring up a block plug and snapping it into place on your HyDip device to get it talking to your laptop. Read more about HyDip online tank management here.

We've just added some notes on connecting magnetostrictive sensors to the HyDip documentation.

Which gauge for you?

Selecting the right gauge for your situation can require discussion and thought. Cost, suitability, ease of installation and accuracy are just some of the factors that figure in a decision.

As well as magnetostrictive gauges your choices include: