Water Acvity E.R.H % Wall Guide
Why measure water acvity ? â€˘ â€˘ â€˘
Water ac$vity ( Equilibrium % Rela$ve Humidity ) is the free moisture available. Water ac$vity is scaled 0 -1 aw or 0- 100 % ERH . Water ac$vity can determine the quality of your products or ingredients as a tool for micro â€“ growth poten$al, stability, texture , taste and shelf-life Quality Control measures.
Taking reliable readings : â€˘ â€˘ â€˘ â€˘
Always let warm or cool samples reach room temperature before opening ! Ensure samples are homogenised (crushed, s$rred or mixed-up evenly). Prepare samples in the plas$c cups provided and fill to approx. 2/3 full. Maybe you could write up a simple test procedure (SOP) ?
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Calibrate against the re- useable SAL-T salt tablets at least every 2 months. Change the sensor protec$ve filter ( EVC21) every 2 months at least . Keep the sensor chamber clean and free of sample build up. Ensure that rou$ne maintenance and calibra$on is carried out by Novatron .
Calibraon & maintenance :
What readings to expect :
Microbiological growth potenal ( spoilage ) : WAT E R A C T I V I T Y C H A R T %RH a w Va l u e s
Growth limits of micro-organisms
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Novatron Scientific Ltd, 46 London Rd, Horsham, West Sussex RH12 1AY . T 01403 754416 F 01403 754480. email@example.com www.novatron.co.uk UKAS laboratory no. 0669 . ISO 9001 : FS540804
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