3
D6F-PH MEMS Differential pressure Sensor User’s Manual (A288)
4. Principle of Pressure detection
By using a thermal mass flow sensor, Omron’s MEMS differential pressure sensor can detect
fine changes in differential pressure.
Fig. 3 Principle of differential pressure sensor
(a) and relationship between flow rate
and differential pressure (b)
5. Features of Product
By using a thermal mass flow method, Omron’s MEMS differential pressure sensor is more
sensitive compared with that of a conventional differential pressure sensor in the low-pressure
range.
Fig. 4 Comparison with conventional method and thermal mass flow method
Orange
：
thermal mass flow method
Blue
：
conventional method
chip
v
Vout
∝
2
main
v
p
∝
∆
Thermal mass flow method
The output of Omron’s sensor is
proportional to the square root of
the gas flow rate through the
sensor chip surface.
Conventional method
The output of a conventional
sensor is proportional to the
square of the gas flow velocity
through the main channel.