Noisy data in NI data logger USB-6225

[MJ2520]

Hi,

Regarding the NI data logger USB-6225, I'm wondering if you or anyone else has some expertise with it? I'm encountering an issue where the measurement data becomes noisy and fluctuates every 15 minutes when it is connect to the battery source.

Additionally, when I connect it to the voltage sensors, the readings fluctuate significantly between the actual measurement point and the maximum range (10 V). Interestingly, when I measure the sensor output with a multimeter, the reading is stable. Can it related to calibration time (because Max show 2011 on calibration date)? If yes what can I do? I try self-calibration but it is not useful.  Any insights or suggestions you might have would be greatly appreciated.
I use 

NI-DAQmx

Version: 2024 QC

NI -DAQmx Runtime

Version: 2024 Patch 1
Flexlogger 2024

[DMycroft]

Hello MJ,

I knew you faked your death.

Here are some steps and resources to address your issue:

1. Calibration

   • Your device is overdue for a factory calibration. NI recommends annual calibration for best accuracy.

   • Self-calibration only adjusts for minor internal errors; it cannot compensate for hardware drift over 13+ years.

   • NI Calibration Services can restore accuracy.

2. Software Configuration

   • Double-check your DAQmx and FlexLogger channel settings: input range, filtering, and sampling rate.

   • Try enabling software filtering or averaging in FlexLogger to reduce noise.

3. Compare with Multimeter Setup

   • Note that your multimeter may have built-in filtering and higher impedance. Try to replicate its wiring when connecting to the DAQ.

4. Test with Known Source

   • Connect the DAQ to a stable, known voltage reference (e.g., a precision voltage source or a battery with a resistor divider) to see if the noise persists.

To summarise:

• Your USB-6225 is overdue for calibration, which is likely contributing to inaccurate and noisy readings.

• Grounding and wiring practices are crucial, especially with battery-powered sources.

• Software configuration and signal conditioning can help reduce noise.

Please let me know if you need help arranging calibration, or if you can share more details about your setup for further troubleshooting,

Dom