Question about local HRV Value

[Drzhivago264]

Hello, thank you for the repo, I am modifying your work for a school project.
However, I do not have prior knowledge about heart rate. Since the value produce by my H9 in OpenHRV is significantly lower than in a mobile app (SparkVue) so I guess that I have done something wrong.

Currently, I am emitting HR like this:

    def update_hrv_buffer(self, local_hrv):
        if not self._hrv_buffer[0]:
            return  # wait until buffer is full
        threshold = max(map(abs, self._hrv_buffer)) * 4
        if local_hrv > threshold:  
            print(f"Correcting outlier HRV {local_hrv} to {threshold}")
            local_hrv = threshold
        self._hrv_buffer.append(local_hrv)
        self.hr_update.emit(f"Heart Rate: {str(local_hrv)}")
        self.update_mean_hrv_buffer()

Here is the result:

How should I interpret the local_hrv and how can I convert it to normal heart rate (I am not quite sure what is normal but probably somewhere around 80?)
Thank you for your time and help