Do gas and leak measuring devices work for liquid products?
In the food industry, the nature of the packaged product (dry, solid, liquid or pasty) directly influences how the quality of the packaging is controlled. If the measurement of protective atmosphere (MAP) and tightness is simple on dry products, a question frequently arises in laboratories: can we check packaging containing liquid or semi-liquid products?
The answer is yes, it’s entirely possible, but this requires understanding a physical rule that is essential to protect equipment and ensure reliable results.
The secret of measurement: control the gas, not the liquid
To analyze the composition of gases (O₂/CO₂) or search for a leak by pressure variation, devices on the market never immerse their sensors directly into the liquid. They operate by suction of a gaseous fluid.
The control of a liquid product (soup, juice, dish in sauce, marinade) is therefore perfectly feasible, under a strict condition: the packaging must have a “head space”, that is to say an air or protective gas pocket located above the product.
It is this pocket of gas that will be collected and analyzed. However, the coexistence between a liquid and an electronic measuring instrument requires addressing two major technical challenges on the production line:
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The risk of accidental liquid aspiration
To perform the test, a needle pierces the film or the packaging seal. If the gas bag is too small, or if the packaging is handled suddenly, the liquid may be sucked directly into the device circuit. This phenomenon instantly leads to needle clogging or filter saturation, and requires a technical intervention to clean the system before testing can resume.
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The disruption of the sensors by moisture
Even without directly vacuuming the product, liquids or sauces generate high ambient humidity inside the packaging. If this moisture or micro-droplets infiltrate the device, it can clog the measuring cells and temporarily distort the results (error messages, false alerts of non-compliance), thus slowing down the pace of operators at the end of the line.
Put simply: Testing a liquid product packaging poses no technological problem, as long as the operator applies the correct method to target the gas pocket without sucking in any fluid material.
How to adapt these measurement requirements to the reality on the ground with the elyos® ?
Since the success of the test depends on the precision of the gesture and the protection of the sensors, the choice of a suitable equipment is crucial. It is within this rigorous framework that the recommendations of our metrologists for using the elyos®come into play.
For purely liquid products (such as juices or oils), it is strongly recommended to avoid using the device. On the other hand, if you package semi-liquid, viscous or juiced products (such as ready-cooked meals or marinades), the elyos® proves to be perfectly capable of validating your packaging, provided that you comply with three strict safety rules:
- Aim strictly at the headspace: The sampling needle must never plunge into the material. It must remain positioned in the upper gas pocket.
- Strategically tilt the packaging: Make the stitching in an area where the liquid has accumulated opposite the needle, in order to artificially maximize the size of the gas pocket.
- Use and monitor the protective filters: Ensure that the device’s hydrophobic filter is always fully in place and dry. It serves as the ultimate barrier to block moisture before it reaches the instrument’s sensors.
In summary
To preserve the longevity of your instrument fleet and ensure absolute reliability in your gas and leak analyses, reserve the use of the elyos® with solid, dry packaging or with a sufficient volume of gas.
Learn more about the elyos : click here