Dear Team members,
I am facing a very peculiar situation related to Multi point RTD operation. Here is the scenario.
This multi point RTD( is being used in Hydrogen Generation via Methanol and water reaction. Temperature goes to around 270~280 deg C. There are various region inside the reactor where reaction takes place and this reaction releases the heat. This temperature is measured by the Multi point RTD. In our case, there are 6 RTDs in this Multi point RTD. This RTD is connected from the bottom without any thermowell.
After one of our SDM, this RTD started malfunctioning. This RTD was showing less than normal as compared to before. Following things done after identifying instrument malfunction.
1. RTD connection to DCS removed and a rheostat was connected to each point. No problem found with the DCS card or cable. DCS value was corresponding to the resistance of rheostat.
2. RTD connection removed at field and resistance was measured. We found that the resistance corresponds to the temperature. Its only when connected with DCS, the temperature drops for all 6 RTDs.
3. Just to confirm, we connected the Multi point RTD with a Temperature recorder. Then also the temperature drops for all 6.
We are not able to identify the problem. Discussion with the vendor also did not solve the problem. So i was hoping to get some insights from this group
I am facing a very peculiar situation related to Multi point RTD operation. Here is the scenario.
This multi point RTD( is being used in Hydrogen Generation via Methanol and water reaction. Temperature goes to around 270~280 deg C. There are various region inside the reactor where reaction takes place and this reaction releases the heat. This temperature is measured by the Multi point RTD. In our case, there are 6 RTDs in this Multi point RTD. This RTD is connected from the bottom without any thermowell.
After one of our SDM, this RTD started malfunctioning. This RTD was showing less than normal as compared to before. Following things done after identifying instrument malfunction.
1. RTD connection to DCS removed and a rheostat was connected to each point. No problem found with the DCS card or cable. DCS value was corresponding to the resistance of rheostat.
2. RTD connection removed at field and resistance was measured. We found that the resistance corresponds to the temperature. Its only when connected with DCS, the temperature drops for all 6 RTDs.
3. Just to confirm, we connected the Multi point RTD with a Temperature recorder. Then also the temperature drops for all 6.
We are not able to identify the problem. Discussion with the vendor also did not solve the problem. So i was hoping to get some insights from this group