Brother MFC-9840CDW User Manual page 238

Noise level
Temperature
Humidity
222
Sound power
Operating (Copying): LWAd = 6.9 Bell
Standby:
Sound pressure
Operating (Copying): LpAm = 54.5 dBA
Standby:
Operating:
Storage:
Operating:
Storage:
LWAd = 4.4 Bell
LpAm = 30 dBA
50° F to 90.5° F (10 to 32.5° C)
41° F to 95° F (5 to 35° C)
20 to 80% (without condensation)
10 to 90% (without condensation)