Part 3: Competition – Catalytic Combustion Sensor Technology
Control Instruments is a major manufacture of catalytic sensors. While well-suited for many area monitoring applications, we rarely recommend them for process measurement. By their very nature, catalytic beads are relatively slow devices.
In industrial process applications, it has been determined by Domestic and International agencies (NFPA-86;Americas/ EN 1539; Europe) that a response time of less than a few seconds be required to prevent upset conditions.
System response time is the sum of the sample delivery time plus the sensor response time. This further emphasizes the importance of short sample delivery lines and no sequential sampling. Of the sensor choices listed in Annex E of the National Fire Protection Agency’s NFPA-86, “catalytic sensors have the longest response times”.
It is therefore important to have an analyzer that can do the job quickly, reliably, and provide consistent and repeatable results.
Here is a Case History of a customer who was using Catalytic Sensing System to protect their RTO and how they needed a quicker response time.
In order to accurately measure and optimize the process, here are some points to consider when choosing the proper technology:
- What is the required response time of the entire system?
- How quickly can the device make an alarm? Is the time-to-alarm less than a few seconds?
- What compounds, other than solvents/combustibles are present in the sample stream?
- Are there corrosive agents or coatings that can poison the sensor leaving it unusable?
- Is the sensor FAILSAFE?
- For the solvents to be measured, now or in the future, how different is the response of one to another? How much error results from measuring different solvents?
- Can the device be calibrated according to code and still allow dryer operation without false alarms?
The sensor must be appropriate for the application. Having in-depth knowledge of what type of analyzer is best suited to the process environment, allows us to help our customers implement the best safety systems while allowing them to operate economically.