SENSORS & MEASUREMENT
THE SPEC SHEET CONUNDRUM
Russell Culver, from Swan Analytical, explains why some of the key differentiators of instrumentation, such as ease and cost of maintenance, are not shown in specification sheets
T
he leading providers of continuous water quality monitoring instrumentation frequently claim similar levels of performance, so it can be challenging to choose the best measurement technology with which to entrust critical manufacturing processes.
Continuous monitoring equipment plays an essential role in most manufacturing processes, protecting product quality, lowering costs, avoiding waste and ensuring regulatory compliance. For the purposes of this article, we will study the monitoring of total organic carbon (TOC) in purified water systems. The quality of purified water is particularly important for most manufacturers, but especially so for the manufacturers of pharmaceuticals, medicines and personal care products. Cutting-edge measurement technology is therefore essential to ensure the quality and reliability of purified water systems. TOC is a particularly important
measurement in pure water systems because it provides a failsafe method to immediately detect any unwanted organic content. Contamination may result from sources present in the supply water and not removed by the purification process. However, contamination may also arise from within the high purity water system itself. Continuous monitoring, a fast response time and reliability are therefore essential,
TOC is one of the four critical parameters
defined by the Pharmacopeia to ensure the quality of purified water (PW) and water for injection (WFI).
The objectives of the United States Pharmacopeia standard USP <643> are to ensure the accurate measurement of TOC and to provide guidance on how to achieve that goal. USP <643> does not specify a particular analytical method, however it does specify the criteria for qualifying TOC instrumentation and for the interpretation of results. For example, instruments should be
16 JUNE 2025 | PROCESS & CONTROL
The accuracy and performance of Swan’s AMI LineTOC analysers are equivalent to other leading manufacturers, but for many users a key point of differentiation is the ease of maintenance. Model shown is for purified water (cold). A hot water version is also available
Case study - pharmaceutical manufacturer One of Swan Analytical’s customers is a well- known global brand in the body care and fragrance sectors, with a UK manufacturing facility using purified hot and cold water for both manufacturing and cleaning purposes. The level of purification is critical for the quality of their products, so a comprehensive continuous water quality monitoring network has been established for quality control and regulatory compliance.
The company takes an uncompromising approach to quality, covering every stage of the development and manufacture of its products, with rigorous compliance to some of the strictest regulations in the world. Its manufacturing facilities also feature the most advanced testing equipment to guarantee product quality. All manufacturing equipment is tested and certified, and every production process is validated.
able to distinguish between organic and inorganic carbon, and must have a detection limit specified by the manufacturer of 0.05 mg/L (equivalent to 0.05 ppm or 50 ppb). Also, instruments must be calibrated according to the manufacturer’s instructions and regularly subjected to a System Suitability Test (SST). Continuous TOC monitoring is also specified in European standards. For example, the EU GMP Annexe 1 requires water for injection systems to include continuous monitoring systems such as TOC and conductivity, (unless justified otherwise) as these may give a better indication of overall system performance than discrete sampling. Sensor locations should be based on risk and the outcome of qualification. One of the key challenges facing process managers is how to choose instrumentation when all the spec sheets look the same! This is because measurement instrumentation frequently employs the same or similar detection technology, so performance measures such as accuracy and resolution are inevitably similar. The key differences between different manufacturers therefore mainly relate to issues such as measurement stability, reliability, and ease of use. However, these characteristics are difficult to define on specification sheets, but feature prominently in the minds of existing users.
Local engineering staff say key product differentiators are the ease and cost of maintenance procedures such as service and calibration. These are not issues that can generally be assessed in product literature, so it is necessary to learn from the experience of existing users. However, in this example, the user already had the prior benefit of an existing Swan chlorine analyser which was employed to continually check the performance of a carbon filtration system. This provided the level of confidence necessary to subsequently deploy a Swan analyser for the measurement of TOC. Importantly, the client chose Swan, not because it was more accurate than its predecessor, but because it was so much easier to manage.
Swan analysers are simpler to maintain because they have a modular design. This means that the footprint is very slightly larger, but importantly, service and calibration work is improved, because it is easier and less costly to work on or replace individual modules. In addition, the Swan analysers come with a 3- year warranty, quite unusual in this market. This is an extract of a longer feature. To read the full story, please visit:
https://processandcontrolmag.co.uk/how- to-select-water-purity-monitors-for-24-7- reassurance/
Swan Analytical
uk.swan.ch/
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40
