Frequently Asked Question
This refers to the Generic 2/3 Wire RTD Configurations in exSILentia. We find that the Generic 2/3 wire RTD close coupled, Low stress lamda du = 173 and RTD Extension wire, Low stress lamda du =95. This data points in the direction that close coupled is b
Last Updated 5 years ago
The close coupled failure rate you are referencing is for a high stress environment (173 FIT). In this case the close coupled failure rate is higher than the extension wire option that you listed which is for low stress environment (95 FIT). So you are mixing the two different operating profiles.
However the data is indeed suggesting for same operating profile that close coupled has a lower failure rate than extension wire. This failure rate is the failure rate for the wiring only, not the potential impact the environment has on the transmitter. What the data is suggesting is that in case of extension wires there is a higher failure rate than if the transmitter is close coupled, simply because there is "more wire" to fail...
You are hinting to good engineering practice to mount the transmitter remotely from the compressor etc. to minimize the impact on the transmitter. This is a different issue. Higher stress will absolutely impact the likelihood of failure of the transmitter, however our data does not distinguish between operating profiles for the transmitter. As a user you need to make sure that the transmitter is deployed in an environment that is suitable for it based on the transmitter's specification. If the transmitter has a higher likelihood of failure due to close coupling of the high vibration machine, than the failure rate data for the transmitter should be adjusted appropriately.
However the data is indeed suggesting for same operating profile that close coupled has a lower failure rate than extension wire. This failure rate is the failure rate for the wiring only, not the potential impact the environment has on the transmitter. What the data is suggesting is that in case of extension wires there is a higher failure rate than if the transmitter is close coupled, simply because there is "more wire" to fail...
You are hinting to good engineering practice to mount the transmitter remotely from the compressor etc. to minimize the impact on the transmitter. This is a different issue. Higher stress will absolutely impact the likelihood of failure of the transmitter, however our data does not distinguish between operating profiles for the transmitter. As a user you need to make sure that the transmitter is deployed in an environment that is suitable for it based on the transmitter's specification. If the transmitter has a higher likelihood of failure due to close coupling of the high vibration machine, than the failure rate data for the transmitter should be adjusted appropriately.