Moisture measurement is a critical task in many industrial and laboratory settings. A precise way to calibrate and validate moisture analyzers is through the use of known moisture generation sources. Insight Analytical's moisture generator block is a versatile tool designed to validate moisture analyzers, compact, and portable, while having quick response times, enabling the generation of known concentrations of water vapor in carrier gases. Let's delve into the intricate workings of this system and understand how it can be an asset in your moisture analysis regime.
The moisture generator block is a robust piece of equipment used to provide a source for online or in-lab moisture analyzer validation.
It allows for the generation of a known concentration of water vapor in a carrier gas. Carrier gas can be anything from nitrogen from a cylinder to natural gas directly from your pipeline.
A high-pressure carrier gas is introduced into the system. Inside the block, the flow is split into two paths:
The unique feature here is a fixed dilution ratio between the two sides, ensuring precision in concentration generation.
Initial measurements are carried out with only the dryer active to establish a reliable zero point. Using a moisture analyzer like the Tiger Optics cavity ring-down spectrometer, the dry gas can be seen to contain about 81 parts per billion (ppb) of moisture.
By altering a valve, the moisture generation side is engaged, allowing the carrier gas to flow through the moisture generator and mix with the dry gas. The internal mechanics, including the fixed dilution ratio, are calibrated for each generator block and are provided along with a spreadsheet designed for accurate water content calculations.
The process involves observing the moisture analyzer's display and comparing the measured concentration to predicted values derived from the spreadsheet and the saturation temperature of the gas.
For example:
At 200 psi gauge and 22.25 degrees Celsius, a prediction could be around 159 ppb. The actual analyzer reading following equilibration may be close to 161 ppb.
Adjusting the inlet pressure regulator can change the pressure at which the gas is saturated, and subsequently alter the dilution ratio and the concentration of moisture in the gas. Multiple points of calibration can be performed by switching the pressure to different settings, such as 200 psi to 400 psi.
Observing the real-time changes in moisture concentration allows an operator to monitor the equilibration process and stabilization of readings, which can be crucial for ensuring the accuracy of the calibration.
The moisture generator block has several advantages over other calibration methods:
With its robust design and intuitive operation, the moisture generator block simplifies the validation of moisture analyzers. The ability to quickly confirm linearity and repeatability gives analysts confidence in their moisture measurement data.
Feel free to click on the links above to delve deeper into the topics that interest you. We appreciate your interest in our products and expertise! If you have any further questions, don't hesitate to reach out.
- Hamish Adam PRESENTED AT: L'Analyse Idustrielle, Paris, France Keywords Ultraviolet, Photometers, Absorption, Process Control Abstract Many different analytical techniques have made the transition from the laboratory to online process monitoring. UV photometry has made this transition more easily than most because it possesses some inherent advantages. Simple, robust optics and absence of interference from […]
- Hamish Adam PRESENTED AT: Annual ISA Analysis Division Symposium, Framingham, MA Keywords Ultraviolet, Photometers, Absorption, Process Control Abstract Many different analytical techniques have made the transition from the laboratory to online process monitoring. UV photometry has made this transition more easily than most because it possesses some inherent advantages. Simple, robust optics and absence […]
PRESENTED AT: ISA Analysis Division, Houston, TX Keywords ULTRAVIOLET ABSORPTION SPECTROSCOPY, APPLICATIONS, SULFUR RECOVERY, SCOT CONTACTOR, NATURAL GAS, HYDROGEN SULFIDE Abstract Ultraviolet absorption spectroscopy has been used for decades in the refining and petrochemical industry. Online spectroscopic methods allow for rapid compositional analysis of process streams and provide the capability for real-time monitoring and control. […]
