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Advancements in Dew Point Analyzers

Dew point analyzers hold a crucial place in various industries, providing invaluable insights into moisture levels to ensure operational efficiency and product quality. In this article, we will delve into the intricacies of dew point analysis, encompassing both conventional methods such as chilled mirror measurement and the innovative CEIRS™ technology introduced by ZEGAZ Instruments. Additionally, we will explore the practicality of portable dew point analyzers in specific applications.

What is Dew Point Analysis?

Dew point analysis is a fundamental process employed across diverse industries. Every gas turns into liquid if cooled enough. This is the moment at which the transition from the vapor phase to the liquid phase happens. In most industries, the moisture dew point is an important figure. This is the temperature at which moisture condenses out of a gas mixture and water droplets begin to form.

In natural gas measurement, there is an additional and equally important dew point; the Hydrocarbon Dew Point (HCDP). This is the temperature at which hydrocarbons start to condense out of natural gas to form hydrocarbon liquids. Both moisture dew point and hydrocarbon dew point are extremely important in analysis of natural gas.

The moisture dew point and the hydrocarbon dew point of natural gas depend both on the pressure and the composition of the gas. Precise measurement of both dew points is of paramount importance in controlling the quality of natural gas at various points from extraction, refinement, transport, and distribution of natural gas.

Dew points can only be measured using the fundamental chilled-mirror process. All dew point analyzers are adaptation of the chilled-mirror principle. In the chilled-mirror principle, a surface is cooled until condensation begins to form on it. If the condensation is moisture, then the temperature at which it forms is called the moisture dew point. If the condensation is a hydrocarbon, then it is the hydrocarbon dew point. Most traditional chilled-mirrors have issues distinguishing between the hydrocarbon and moisture dew points. However, with the advent of CEIRS(™) (Chilled-mirror Evanescent IR Spectroscopy), that shortcoming has been addressed.

Dew Point Analyzer
A dew point analyzer is a device used to measure the dew point of moisture within a sample of natural gas.

Portable Dew Point Analyzers: Enhancing Flexibility

Portable dew point analyzers offer a flexible solution for spot checks, inspections, or scenarios where continuous monitoring is unnecessary. These analyzers are thoughtfully designed to provide convenience and adaptability in measuring moisture and hydrocarbon dew points. They offer an efficient means of assessing dew points levels on the go, contributing significantly to the effective management of dew points in natural gas.

Chilled Mirror Measurement: A Traditional Approach

Chilled mirror measurement is a first-principal measurement. For more on the concept of first-principal measurements, see the blog post on this important topic. Chilled-mirror measurements, both manual and automated, play a valuable role in the realm of dew point analyzers. This method involves cooling a mirror surface until moisture from the surrounding air condenses upon it. The temperature at which this condensation occurs is recognized as the dew point. While effective, this approach has limitations, particularly in its ability to distinguish between various dew points in gas mixtures.

CEIRS™ Technology: Pioneering Advancement

CEIRS™ technology, introduced by ZEGAZ Instruments, represents a significant advancement in dew point analysis. CEIRS™ stands for "Chilled-Mirror Evanescent Infra-Red Spectroscopy." Unlike traditional methods that rely on mirror condensation, CEIRS™ uses infrared spectroscopy to detect the onset of condensation at dew point temperatures. This technology offers several key advantages:

  • Precise Differentiation: CEIRS™ technology can differentiate between various dew points in gas mixtures, including hydrocarbon and water dew points, a crucial capability for industries requiring specific moisture control. This is enabled by the use of IR spectroscopy to distinguish between the chemical structure of moisture and hydrocarbons.

  • Resistance to Contaminants: CEIRS™ technology is highly resistant to interference from contaminants, debris, or liquid droplets, reducing the need for frequent maintenance.

  • Enhanced Accuracy: CEIRS™ technology provides highly stable and accurate measurements, making it an industry standard for fully automatic measurements of natural gas quality.

Final Thoughts

Dew point analysis is a critical process in industries where precise dew point control is indispensable. While traditional methods like chilled mirror measurement continue to serve their purposes, technological advancements such as ZEGAZ Instruments' CEIRS™ technology are elevating accuracy and reliability to unprecedented levels. Portable dew point analyzers, too, are emerging as indispensable tools, offering flexibility and convenience in specific applications. As industries persist in relying on dew point analyzers to safeguard operational efficiency and product quality, ongoing technological evolution promises to play a pivotal role in meeting these demands.


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