8/30/2020 11:49 PM | |
Posts: 1 Rating: (0) |
Hello Barsice, I have same problem with "Seko Kontrol 50" water PH meter. when applying 4-20 ma analog signal externally from a current generator to the AI input it shows a stable signal. Have spent lot of time but not find out any solution. If you solved your problem then can you share me the solution please? Jonardan ------------------------------------------------------------------------------------------ |
Last edited by: Jen_Moderator at: 08/31/2020 12:17:30New subject after splitting |
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9/1/2020 4:38 PM | |
Joined: 7/7/2010 Last visit: 5/17/2024 Posts: 14751 Rating: (2372) |
How is the PH Meter wired? Where is the 24V supply and 0V return in the current loop path? In cases where signal isolation is required to fix a current loop, you can use a 4-20mA to 4-20mA signal conditioner with galvanic isolation. It raises the cost for each PH meter, so it is worth making sure the wiring is correct. If the current loop wiring is landed on terminal strips with a 500Ω resistor across the terminals, how stable is the voltage? Feel free to use a spare analog input configured for voltage (0-10V or ±10V) and check across the terminals with the resistor installed. If it starts to fluctuate, consider putting a 1MΩ resistor from the AI module's 24V power supply 0V and the - input (to simulate a multimeter connected measuring the - input to PE).
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science guy |
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