Page 69 - FoodFocusThailand No.198 September 2022

STRONG QC & QA

Dissolved Oxygen (DO) Detection velocity requirement, so false DO level alarms
To a great extent, beer quality is associated with the are eliminated. Fluorescence quenching
quantity of dissolved oxygen (DO) it contains. Oxygen reacts technology determines oxygen in liquids very
with proteins and polyphenols in the beer which leads to quickly; therefore, the response time of the
non-biological instability resulting in reduced shelf life and sensor is extremely fast. Additionally, the
adversely affected flavor. Consequently, controlling DO levels unique optical DO sensor detects DO levels
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during beer production is always a quality target that down to 2 ppb. Combined, this means a sensor
Tsingtao focuses on. During production, a significant is an excellent tool for reducing out-of-spec
proportion of dissolved oxygen comes from the filtering production.
process. Therefore, before the product enters bright beer
tanks, inline detection of DO prevents out-of-spec beer from More Sturdy and Less Maintenance
reaching the filling line. Tsingtao Brewery also appreciates this unique
Since 2003, the brewery has employed the renowned optical DO sensor’s reduced maintenance
2
inspection equipment company . in-line DO measurement benefits. Firstly, sensor drift is very low, so
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equipment for fermentation tanks and filters as well as on calibration is required less frequently than for
other brewery processes. As production at the brewery has amperometric probes. Secondly, whereas
increased, CIP cycles have become a significant daily maintenance on amperometric sensors
operation. The probes must be withdrawn from the process involves changing membrane and electrolyte,
pipes during CIP and reinserted to prevent damage to DO with the unique optical DO sensor the only part
2
sensor membranes from chemicals and high temperatures. that requires periodic replacement is the
All of which are time consuming for operators. individual oxygen sensing element. The
exchange is simple and can be completed in
Faster with Optical Technology under a minute.
The renowned inspection equipment company suggested a The probe features with the Intelligent
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switch from an amperometric measurement system to one Sensor Management (ISM) technology from
based on optical technology. The special optical DO the renowned inspection equipment company .
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sensor exploits the phenomenon of fluorescence quenching ISM brings additional maintenance benefits
to determine trace oxygen levels. No membrane is that help sustain Tsingtao’s round-the-clock
involved, and the sensor is largely unaffected by CIP production. Advanced sensor diagnostics
processes. tools displayed on the connected transmitter
But resistance to CIP is not the only benefit of this unique provide real-time data on the probe’s condition.
optical DO sensor . Amperometric sensors are liable to The remaining lifetime of the individual
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incorrectly report high DO levels if flow velocity is too low. oxygen sensing element and when calibration
The unique optical DO sensor has a negligible flow will next be required, as shown by the Dynamic
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Lifetime Indicator and Adaptive Calibration
Timer, mean that maintenance planning is
easy and the risk of sensor failure during production is significantly
reduced.

Fully Productivity
According to Du Shuhai, an engineer at the brewery, “On the
basis of production exceeding 430 million liters in 2009, the
successful application of the unique optical DO sensor meant
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that the dissolved oxygen index of all filtered beer was
maintained below 50 ppb, and both beer quality and output
were improved.”

More Information Service Info C010

ข้้อมููลเพิ่่�มูเติ่มู / Additional Information
1 Mettler-Toledo from the USA
2 InPro 6970i, the unique optical dissolved oxygen sensor from Mettler-Toledo, USA
3 OptoCap, the technology for sensing oxygen for InPro 6790i
InPro 6970i dissolved oxygen sensor
InPro 6970i dissolved oxygen sensor

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