Himayala1 Posted November 12, 2022 Share Posted November 12, 2022 (edited) Hello, I am using an analog discovery. When I use the record function it gives me measurment values with an offset error and a gain error. +100mV The normal scope values basically differ from the record values. Why is it doing this? How can I change my record values, meaning: rectify offset and gain error, so I get good values? Edited November 13, 2022 by Himayala1 Link to comment Share on other sites More sharing options...
1 attila Posted November 14, 2022 Share Posted November 14, 2022 Hi @Himayala1 The maximum record rate with Analog Discovery (1&2) is about 1MHz. Himayala1 1 Link to comment Share on other sites More sharing options...
0 Himayala1 Posted November 14, 2022 Author Share Posted November 14, 2022 (edited) Thank you for the response attila. The rate was just 50Hz. I used the record to file button btw. Edited November 14, 2022 by Himayala1 Link to comment Share on other sites More sharing options...
0 attila Posted November 14, 2022 Share Posted November 14, 2022 Hi @Himayala1 Are you comparing captures with the same rate ? At different rates higher frequency components may be sample/averaged differently. Here I compared the following which overlap, except the sub-sample trigger positioning which is not applied for the imported data. C1 - Rec. 200@50Hz 64bit + Import Bin R1 - Record 200@50Hz R2 - Single 4sec@8kHz Himayala1 1 Link to comment Share on other sites More sharing options...
0 Himayala1 Posted November 14, 2022 Author Share Posted November 14, 2022 Hi @attila thank you a lot for the help. I am only measuring one signal. The sample rate of the recording and the normal scope are indeed not the same. is this the reason? Link to comment Share on other sites More sharing options...
0 attila Posted November 15, 2022 Share Posted November 15, 2022 Hi @Himayala1 It could be... Could you attach some screenshots or WaveForms workspaces with data ? Himayala1 1 Link to comment Share on other sites More sharing options...
0 Himayala1 Posted November 17, 2022 Author Share Posted November 17, 2022 (edited) Yes of course, Data with offset and gain.csvthank you a lot in Advance for your help! The values in the CSV should have been 1228 instead of 1372. It confuses me a lot! Anemometer Geschwindigkeiten.dwf3work Edited November 17, 2022 by Himayala1 Link to comment Share on other sites More sharing options...
0 attila Posted November 18, 2022 Share Posted November 18, 2022 (edited) Hi @Himayala1 The 16bit format samples are raw samples. To convert these to voltage see the note in the record dialog, like: V = 59.1970011866 * 1372 / 65536 - 0.002321186682 These range and offset values depend on the device/channel calibration. The 16bit format may be useful for long records with binary, wav, tdms saving to reduce the file size. The 32-64bit float values represent voltage, like 1.1 is 1.1V, these do not need conversion like the 16bit format. Edited November 18, 2022 by attila Himayala1 1 Link to comment Share on other sites More sharing options...
0 Himayala1 Posted November 18, 2022 Author Share Posted November 18, 2022 Thany you @attilaso much. Have a beautiful day! Link to comment Share on other sites More sharing options...
Question
Himayala1
Hello,
I am using an analog discovery. When I use the record function it gives me measurment values with an offset error and a gain error. +100mV
The normal scope values basically differ from the record values.
Why is it doing this? How can I change my record values, meaning: rectify offset and gain error, so I get good values?
Edited by Himayala1Link to comment
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