Sight Glass & Level Indication Alternatives

Many food and beverage producers require knowing exactly how full their production tanks are at all times. In some cases, the amount of headspace will alter how to treat a product. In other cases, large tanks might be used for serving, which would require knowing how much product is moving in & out. Regardless of the reason, if being able to see the internal fill level is necessary, a sight glass is an ideal solution!

What exactly is a sight glass? Well, in simple terms, “…a ‘sight glass’ can refer to several types of units that allow observation of a process fluid or a feature inside of a pipe, tank or vessel.”1 More or less, a sight level will allow you to precisely measure how full your tanks are, and how much product is being let in or out. As you can imagine, this is incredibly helpful if you’re needing to keep an eye on how full your tanks are.

What if you don’t have a sight level? What if you CAN’T attach one to your tank? If you find yourself in this boat, you are not alone and there are a couple different ways to tackle your problem.

One option would be a floating level indicator. A floating indicator functions how you might imagine…

A continuous level float functions by means a sensor (which can range anywhere from two to 25 ft in length) is inserted at the top of the tank through either a flanged, welded, or screwed connection. The accuracy of level measurement using this type of device is approximately up to .02 in. and as a result is used in many applications requiring high precision in measurement.

Another option that might work would be to simply weight your tank. This option would require zero alterations to your existing equipment, however it would require a large, industrial scale, as well as some precise mathematics. For this application, one would need to know the weight of the empty tank, the weight of a full tank and the weight of your product (whichever volume measurement works best). By plugging these number into a fairly equation, one can determine how much liquid is leaving/entering, based on the weight of their tank.

One last option might be using a laser level. A laser level would typically be installed on the top or lid of the tank. Then, the device projects a laser downward and measures the distance from top of tank to the liquid level. A simple calculation from that, will tell the operator any volume changes needed.

Overall, there are many options outside of the traditional transparent tube that you think of when you hear “sight glass”. Despite all these options, the traditional design seems to be easiest, and most desired for producers. These alternatives are exactly that, alternatives. They can get the job done and are often a better solution than seeking out alterations on an existing tank. However, the tried-and-true sight glass will most likely remain the most accurate and efficient way of knowing how full your tanks are. Contact CSC