Why is there signal drift on the Respiratory Flow Head (MLT1000L)?

With the mouthpiece and filter attached directly to the flow head, some users have reported unacceptable drift in their volume calculations. This can happen for the following reasons: 
  • By not using clean bore tubing
    • ADInstruments recommends using clean bore tubing to alleviate non-laminar flow across the mesh that may occur from this configuration.
  • Temperature drift
    • Make sure the Spirometer Pod / Amp is turned on so the internal circuitry is allowed to warm-up prior to starting the experiment.
    • Do not place the Spirometer on the PowerLab or other electronic equipment as this may cause the Spirometer to heat resulting in temperature drift.