8. Technical notes for the product performance
8.1
Measurement principle
T
he products utilize the Company’s proprietary micro
-machined
(MEMS) calorimetric sensing and data process technology. A thermal
signal generator with a pair of sensing elements at up and downstream
of the microheater is precisely manufactured and separated at
predefined micrometer distances on a chip surface with excellent
thermal isolation. When a fluid is flowing through the sensing chip, the
fluid carries the thermal signal downstream. The sensing elements
register the temperature differences, further correlated to the fluid
mass flow rate via the calibration process.
The calorimetric sensing approach offers a large dynamic range with a
better performance against the environmental parameter alternations.
Please refer to the company's US patents and other publications made available to the public for
additional information.
8.2
Precautions for the best performance of the product
8.2.1
Comparison with a third-party reference meter
It is very common that a user may compare the data from the product with a third-party reference
meter, and in many cases, there could be some discrepancies.
When performing such a comparison, please note that the reference meter should have a better-
specified accuracy (about 1/3 of the product), and pay special attention to the differences in the
reading accuracy and full-scale accuracy.
A full scale accuracy = reading accuracy x (full scale flow rate/ set point (current) flow rate)
Another key point to comparing the different flow meters is that as long as the fluidic flow is a
continuous flow without pulsation, then the fluidic dynamic will have the system following the
Bernoulli equation:
Figure 8.1: Measurement
approach illustration.
34
|
P
a
g
e
http://www.jetec.com w
om.tw/
.t
電話：
0
4
-
23729418 傳真：04-23724011 Email：[email protected] LINE：@jetec
MF5000 User Manual
