{'fraction_non_alphanumeric': 0.012877939529675251, 'fraction_numerical': 0.0, 'mean_word_length': 5.140893470790378, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Selecting Instruments to Ensure a Clean and Healthy Environment

There are strong pressures on the designers of process plants to pay increasing attention to the impact their plants have on the environment. This applies both to new plants and to existing plants which may require process adjustments to make them more benign environmentally. While the response to this environmental challenge may be largely determined by general company policy, many stategic decisions, such as which type of flue gas desulphurisation process to introduce or the method of toxic waste disposal, will often hinge on instrumentation issues. The plant manager must ask which of the parameters essential for environmental protection can be monitored on-line. If the variables cannot be measured directly, can they be inferred from other real-time data? Will the measurements be sufficiently accurate and reliable to demonstrate compliance with terms of consent for continued plant operation? What is not in doubt is that process control, measurement and analysis are decisive in any consideration of environmental matters. Of course the instrument engineer has always had a key role to play in the design of process plants and he or she in early career development soon becomes familiar with the specification and selection of instruments for the most often measured industrial quantities such as pressure, temperature. flow. level, etc. However the selection and sourcing of instruments to measure CFCs and NOx concentrations in air, or to analyse toxic levels in waste effluent, may be less familiar to the young instrument engineer. Even the most experienced instrument engineer will acknowledge that he or she will not be up to date with all the techniques and equipment from all the different vendors.