Portable measurement instrument for accurate and fast water activity (aw) determination Leading by: Innovation & Design Speed & Accuracy Price & Performance „All life needs water!“ Air and water There is no life without water! the important elements on „Water“ is the main component of food and biological materials. The earth for any life accurate determination of its form, nature and amount helps crucial to affect the structure respectively the physical and chemical properties of a product. Water has also a main influence on the mass transfer, on chemical reactions and the activity of microorganisms. Water is stored in every product, either in the bound form or as free water, which is stored between the compounds. What are the optimum amounts of both The a value measuring method w types of water? The amount of bound water depends on the chemical The sample is put in the measurement chamber, which is air-tight. The nature of the substances used. free water of the sample humidifies or dehumidifies the air volume inside Free water can be affected by production processes as well as by storage the chamber. Only the free water component can do this. This exchange and packing. As well as the use of water, too much „free water“ can takes place until the partial pressure of water vapour saturation = zero. reduce the quality and shelf life of the product. Microorganisms such as A highly accurate humidity and temperature measuring unit continuously fungi or bacteria can have optimum conditions to grow and replicate on determines the climate conditions of the air inside the chamber. If the this intermediate aqueous surface. Their metabolic products are deposited parameters remain stable over a user-adjustable stability period, the on the product and spoil the quality. Too high water activity means limited instrument software determines the stable value and converts it to an a - shelf life. Water activity values, which are too low can spoil the taste, w value. Thereby the display continuously shows the current measurement. texture or appearance. Only an extremely accurate and safe quality measurement of the water activity („free water components“) guarantees quality products! Meaning of „water activity“ (a ) w For a long time the industry has accepted how important it is to check free water. The water activity (a ) measurement forms the basis of this w and provides important information about the quality of a product. Finally it provides information regarding the potential of microbiological growth on the surface and then conclusions can be made about the stability, Important factors influencing measurement accuracy and speed : durability and shelf life of a sample. Water activity is defined as the • Sample and measurement chamber temperature availability of free water in a sample. Only this component takes an active • System control capability part in the exchange with the ambient humidity and can possibly form the • Measurement chamber tightness ideal medium for microbiological growth on the surface. Above the sample, • Sample preparation the humidity is measured immediately after reaching equilibrium in • RH measurement accuracy and measurement speed humidity exchange with the sample (difference in partial vapour of water The measurement speed depends largely on the sample properties. vapour). The equilibrium relative humidity (ERH) is measured in % RH Therefore the ability of how fast the available „free“ water is released to and is related to the aw value as following: the surrounding environment plays a decisive role. The measurement a = ERH W speed provided by the electronics of the instrument is often insignificant. 100 On some oily samples the phenomenon of the second sorption step is known. At first the sample „seems“ in an apparently stable condition but 0...100% RH corresponds 0.00...1.00 aw later (possibly after hours) the a -value increases by a few percent w (breakthrough of the oil barrier). Introduction to a measuring w The equilibrium relative humidity of a product is defined by its water vapour partial pressure on the surface and depends on the chemical composition, temperature, water content, storage environment, absolute pressure and packaging. Chemical and biochemical reactions (e.g. Maillard reaction) proceed more frequently and influence the following product properties: • Microbiological- and chemical- stability (growth, see table) • Content of proteins and vitamins • Colour, taste and nutritional value • Stability of the compound & durability, solubility and texture • Storage and packing There are binding regulations in different regions worldwide concerning The optimisation and stabilisation of the product properties require an the a -value to be reached in foods. The measuring principle applied by w upper as well as a lower a limit. Therefore, constant supervision of this Novasina has been checked by the FDA, UNO, WTO, FAO, AOAC and w quality parameter is essential and necessary for efficient production. FOS (EFSA) and approved. The LabSwift-aw product line Come into the world of water activity measurement! LabSwift-aw - fast, practical, innovative Novasina has developed for more than 40 years water activity The LabSwift-aw unites newest technologies as e.g. the contact measurement instruments for laboratories in the field of Product Quality free infrared sample temperature measurement with the Assurance and R&D. Thanks to the unique measurement technology, maintenance free aw-sensor. This allows efficient and fast a -value w Novasina devices are used and appreciated worldwide. The core determination, which is required especially at the production line. element of each instrument is the electrolytic sensor, which has been The intuitive operation and the clear display are additionally continuously developed and improved over the years. Today this is supports for the user. making sure that each measurement fits the high requirements of the Further features such as the easy handling of samples, the SD card for aw measurement and therefore is performing accurately, quickly and mobile measurement data storage as well as the simple possibility for with a high reproducibility. checking and calibrating the device ease the product quality Following products are suitable for an a inspections considerably. w-value determination : • Various kinds of foodstuff The mechanical construction of the LabSwift-aw makes it possible to • Pharmaceutical products easily replace the aw-sensor if necessary. Due to the fact that the • Chemical products calibration values are stored inside the sensor, the instrument has not • Cosmetic products to be calibrated afterwards. Included in the delivery are also multiple use humidity standards (aw-standards). Therefore on site checks, calibrations and adjustments can be performed at any time. LabSwift-aw - versatile, flexible, mobile Using the standard sample dishes all kinds of liquid or solid samples with a volume of approx. 12 cm3 can be measured. If needed, sensor protection filters can be fitted to allow a coverage of a wide range of possible samples. For portable use, a rechargeable, long life battery is available. With Novasina aw measurement devices almost all kind of samples in Measurement chamber Sensor CM-2 Humidity standards almost all physical states can be measured. It does not matter if samples are powders, gel, liquids, pastes or solids. The availability of sensor protection filters enable more accurate and reproducible measurements on samples with critical additives as e.g. alcohol, acids, bases, chlorine etc.. With the new LabSwift-aw Novasina sets a standard in the field of mobile aw-measurement. This device takes the lead in its class thanks to its easy handling, flexibility, speed and appealing design. LabSwift-aw - unique in function and design • Ergonomic design with large and clear LC-Display Display Protection filters SD card • New developed, intuitive stable value setting • Spring loaded sealed measurement chamber Your advantages : • Resistive-electrolytic sensor with „Novalyte“ technology and • Accurate, reproducible, fast aw-value determination calibration point memory • Easy menu structure and clear display • Infrared sample temperature measurement • Mobile use thanks to a Lithium-Ion battery (optional) • Data logger function with SD card interface • SD card for mobile data storage The data stored on the SD card can be transferred to a PC. For • Test- & calibration functions with Novasina aw-standards visualisation, analysis and archiving Novasina offers as option a PC • Sensor protection filters to avoid contamination & errors software. • Handy carrying case incl. sample dishes & aw-standards www.novasina.com Specifications LabSwift-aw : A -value Sample temperature W Measuring principle : Resistive - electrolytic Surface Infrared-measurement + NTC Measuring range : 0.03 ...... 1.00 a 5....45 °C ( 41......113°F ) w Accuracy: +/- 0.010 a +/- 0.15 °K w In the range of : 0.10....... 0.95 a (10 ...95% rh) 0..... +50°C w Resolution : +/- 0.001 a +/- 0.1°C w Accuracy of control : No temperature control available Mains supply : 5 VDC +/- 6% max. power requirement : 4 W Lithium ion battery 1700 mAh with protection control & "auto load" Power supply : 90....264 VAC, 50 / 60 Hz, output -> 5 VDC Display : Reflective, high contrast LCD - display, dimension: 35x69 mm Operating : 3 multi-function keys including On / Off Communication : SD card interface type : SD / SD data system: FAT-16 / FAT-32 HC Housing : Two-part PVC design housing, measurement chamber aluminium Weight: 1.2 kg / Dimension approx. : 225 x 140 x 85 mm Protection class : IP 30 Measuring chamber : Volume 21.1 ml / standardised sample dishes Spring-loaded measurement head (diameter 40 x 12 mm) Special feature : Intelligent „Novalyte“ measurement sensor CM-2 with calibration point memory Novasina – Swiss quality, flexibility and expertise Since its inception more than 50 years ago, the Novasina company has specialised in the accurate measurement of air and material humidity. The basis of this was the world’s first, self-developed electronic measuring sensor for measuring humidity. This technology is based on the resistive electrolytic measurement principle. This was further developed and improved over decades. This measuring principle is generally the most demanding and most accurate. Modern substances and materials allow continuous improvement and expansion of the area of application of this measuring sensor. Today the highly accurate humidity measurement is among our core competences and forms an important pillar of our success. Intensive research and development further ensures a decisive advantage for us. Novasina sensors and measuring instruments are mainly applied to the area of air and material humidity. This is almost exclusively used in industrial applications as well as in research and development. We continue to develop and produce Novasina precision measuring instruments thanks to many years of experience. We are proud of the „SWISS MADE“ label, which guarantees the highest quality, innovation and durability. The diversity of our customers, business partners and applications as well as our international orientation makes Novasina the competent partner for demanding humidity measurements in the industrial sphere! Customer applications and innovation always come first with Novasina! Manufacturer : For further technical information, see the technical data sheets: Consultation, sales and services: Novasina AG Neuheimstrasse 12, CH - 8853 Lachen SZ Switzerland Phone : +41/ (0)55-642-67-67 Internet : www.novasina.com 003502.00 Fax : +41/ (0)55-642-67-70 E- Mail : info@novasina.ch Subject to technical changes