Questions about Ace AF33

See the instructions for use at https://www.ace-technik.com/documents/products/Media/Bedienungsanleitung%20ACE%20AF-33.pdf?ver=1662972992. According to this document: "The ACE AF-33 measures the alcohol concentration in exhaled air and deduces the blood alcohol content. This means that the margin of error is +/- 0.05‰ (per thousand) for a reference value of 1.00 per thousand and 25°C ambient temperature. Measured results are displayed as a 3-digit numerical value with 2 decimal places (‰ or mg/L) and are interpretable 1:1 (if, for example, the display shows the value 0.36 = 0.36 per thousand). Values measured in % BAC are displayed as 4 digits with 3 decimal places.

...up to 5 per mille... but from 3 per mille you probably can't read the per mille value at all - if you even get that far.

This is specified directly by the manufacturer with regard to calibration: ACE recommends calibration of the sensor built into the instrument approximately every 12 months or after approximately 500 tests with the instrument. Calibration is not mandatory, the accuracy of the AF-33 built into the ACE AF-33 must be maintained. The accuracy of the sensor decreases continuously without calibration. Send the unit with the suffix "Alkomat Calibration Service" to the company address provided with the unit if this happens.

No, :( in mil ‰