Meeting NFPA 86: Speed of Response
We've discussed the 6 essentials of meeting NFPA 86, this week let's take a closer look at the second monitoring requirment: Speed of Response.
We've discussed the 6 essentials of meeting NFPA 86, this week let's take a closer look at the second monitoring requirment: Speed of Response.
Last week we discussed the 6 essentials of meeting NFPA 86. Let’s take a closer look at the first monitoring requirement: Sample delivery system (section 11.6.10.11).
It is recommended that process applications employ active sample draw systems to continuously deliver a sample to the solvent vapor monitor.
Why?
The National Fire Protection Association (NFPA) establishes fire safety standards, including standards for the safe operation of processes. In our world we focus specifically on NFPA86, THE Standard for Ovens and Furnaces.
It addresses the safe operation of Class A, Class B, Class C, and Class D ovens, dryers, and furnaces, thermal oxidizers, and any other heated enclosure used for processing of materials and related equipment.
The industry standard accuracy requirement for a flammable gas sensor is +/-10%. Response factors are therefore one of the most significant influences on accuracy, and can easily introduce large errors. Let's examine this concept when comparing FTA vs IR for process applications.
When comparing FTA vs IR for process applications, its important to remember that few analyzers react the same way to all substances.
An infrared sensor is a narrow-band instrument. It can usually discriminate between the substance of interest and background gases but it does not respond to gases outside of it's narrow range of vision.
Most flammable vapor analyzers respond differently to different vapors. Whenever the process solvent is changed, the analyzer must be either recalibrated or reprogrammed to ensure that it’s measurement of the new solvent vapor is still accurate. This creates a challenge when trying to measure a mixture of solvent vapors, especially when using narrow-banded infrared sensors. Now let's compare FTA vs IR for process applications.
This month we've been comparing FTA vs Catalytic for process applications...now let's see it in action!
A customer of ours who produces high performance materials, industrial specialty chemicals and coating solutions, was using a catayltic sensor where a flammability analzyer would be more beneficial.
The only way to ensure that a sample reaches the sensor is to employ active sampling. This is essential in our comparison of flammability analyzers and catalytic sensors for process applications. So let's focus on an important feature: failsafe performance.
Many fires and explosions occur in facilities which thought they had adequate protection against such hazards. Selecting a sensor which responds accurately to the combustible vapors found in process applications is essential. But so is the speed of response.