Always configure the manometer to display "Pressure" in Pascals on both channels. The ATTMA app reads the value from each channel directly, regardless of units. For example, airflow is typically calculated from the pressure displayed on Channel B. If units other than pressure are chosen for that channel, this will lead to errors. Here are some examples:
Manometer configured correctly. Pressure in Pascals on both channels. Flow pressure used by the app to calculate airflow is 110.6 Pascals.
Manometer configured incorrectly. Channel B is reporting m3/h, not Pascals. Flow pressure is read by the app as 3192 "Pascals", which is incorrect.
To aid in testing in windier conditions, you may find the time-averaging function of the manometer helpful. Choose a time-averaging interval greater than 1 second (which itself is an average of many readings over a one-second interval). Common time-averaging intervals may be 5 seconds, 10 seconds, or longer, as long as the user is aware of the starting point for that interval of measurements. The time averaging function is enabled and disabled from the manometer's screen. Example location shown below.
Manometer configured correctly. Pressure in Pascals on both channels. Flow pressure used by the app to calculate airflow is 110.6 Pascals.
Manometer configured incorrectly. Channel B is reporting m3/h, not Pascals. Flow pressure is read by the app as 3192 "Pascals", which is incorrect.
To aid in testing in windier conditions, you may find the time-averaging function of the manometer helpful. Choose a time-averaging interval greater than 1 second (which itself is an average of many readings over a one-second interval). Common time-averaging intervals may be 5 seconds, 10 seconds, or longer, as long as the user is aware of the starting point for that interval of measurements. The time averaging function is enabled and disabled from the manometer's screen. Example location shown below.