3/19/2015 3:52 AM | |
Joined: 3/28/2010 Last visit: 4/17/2024 Posts: 1029 Rating: (211) |
1) Yes, RTD flying lead wires connect to TH100 transmitter input. 2) I suspect that LC cable length is the distance between temp sensor and transmitter, but I don't have a spec sheet handy. No, the 100m distance limit is typically the limit of the distance between an RTD and temperature transmitter, although I prefer much shorter distances. The maximum cable length for 2 copper wires from the TH100 to the analog input signal (and a DC power supply) module is about 2Km (2,000m) for a 24Vdc power supply. That's why people use 4-20mA, it goes 'forever' and is very noise resistant (whereas RTD signals are weak and prone to noise pickup). 3) No, you don't want a 2 wire RTD. Never use 2 wire RTDs. 2 wire RTDs will ALWAYS have a positive offset error due to the resistance of the copper wire connecting the RTD to the temp transmitter. A 3 wire RTD eliminates the error for all practical purposes. Buy a 3 wire RTD and use all three wires. All three wires must be the same length and gauge (thickness). An RTD signal cannot be paralleled to two different receivers, like a PLC analog input and a digital indicator. An RTD can only go to one receiver. If you need the same temperature reading in two different receivers you need a 'dual element' RTD, which is a 2xPt100, two RTD elements in the same sheath. One RTD element wires to one receiver (transmitter), the other RTD element wires to the other receiver (recorder) 4) The transition is the section between the solid metal sheath and the extension wire. Sometimes there's only heat shrink tubing, sometimes a strain-relief spring http://www.omega.com/temperature/pdf/pr-11.pdf Most times there is 'potting' resin seal around the wires and to keep the MgO inside the sheath and water outside of the sheath. You don't want water to get inside the sheath. Water will short circuit the excitation current and produce bad temperature readings. You need to find a local RTD vendor and have them show you the various styles of RTDs. 5) element. An element is a RTD sensor. Two RTD elements in one sheath is two RTD sensors in one sheath. |
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3/22/2015 8:51 PM | |
Joined: 1/5/2013 Last visit: 4/22/2024 Posts: 275 Rating: (16) |
Hi, Thank you. Yes, I understand you well. You answers are very helpful and great Yes, all of these depends on my application, and I need to get an actions "each action separately" when the temperature arrives 45, 50, and 75 C (regarding my application). So the temperature sensor accuracy is not very important for me; I mean class B is enough. and also the analog input module resolution is also 13 bits is enough to get the temperature values mentioned above and to take an action regarding that. and also I have a tank level sensor, I need to monitor the tanks water or juice level into my HMI screens and also to take an action either by the operator or when the tank level is reaching for example 500 liter. so, I think the 13 bits resolution is enough also. what do you think? thanks in advance |
3/23/2015 5:36 PM | |
Posts: 784 Rating: (52) |
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3/23/2015 5:56 PM | |
Joined: 1/5/2013 Last visit: 4/22/2024 Posts: 275 Rating: (16) |
Hello wago thank you. I hope so and by the way i want to thank you and thank everyone in this interesting forum. thanks again and again :) |
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