Definition And Terminology - SMC Networks PF2W7 Series Operation Manual

■Definition and terminology

Terms
A
Accumulated flow
Accumulated pulse
output
Analogue output
Attachment
Auto-preset
C
Cavitation
Chattering
D
Digit
Display flow range
F Fluid temperature
F.S.
(Full span, Full scale)
H
Hysteresis
Hysteresis mode
I
Instantaneous flow
Internal voltage drop
K
Karman vortex
M
Minimum
setting/display unit
O
Operating humidity
range
Operating
temperature range
The total amount of fluid that has passed through the device. If an instantaneous flow of
10 L/min continues for 5 minutes, the accumulated flow will be 10 x 5 = 50 L.
A type of output where a pulse is generated every time a predefined accumulated flow
passes. It is possible to calculate the total accumulated flow by counting the pulses.
Outputs a value proportional to the flow rate. When the analogue output is in the range
1 to 5 V, it will vary between 1 to 5 V according to the rate of flow. The same for
analogue output of 4 to 20 mA.
A metal part at both sides of the product to connect piping.
This function calculates and sets the pressure values automatically based on the
on-going operation.
A phenomenon that may occur in a fluid moving at high speed. In the parts of the fluid
where the pressure is low, vapour bubbles form and then rapidly collapse. If cavitation
is present for a prolonged period, exposed surfaces will be damaged; this is called
cavitation damage or erosion.
The problem of the switch output turning ON and OFF repeatedly around the Set value
at high frequency due to the effect of pulsation.
Minimum unit for setting/display is 1 digit. When the minimum unit for setting/display is
5 L/min, 3 digits will be 3 x 5 = 15 L/min
The range which can be displayed by the product with a digital display.
Range of fluid temperature that can be measured by the product.
Stands for "full span" or "full scale", and indicates varied analogue output range at rated
value. For example, when analogue output is 1 to 5 V, F.S. = 5[V] - 1[V] = 4[V], (ref.
1%F.S. = 4[V] x 1% = 0.04[V])
The difference between ON and OFF points used to prevent chattering. Hysteresis can
be effective in avoiding the effects of pulsation.
Mode where the switch output will turn ON when the flow is greater than the Set value,
and will turn OFF when the flow falls below the Set value by the amount of hysteresis or
more.
The volume of flow per unit of time. If it is 10 L/min, there is a flow of 10 L passing
through the device in 1 minute.
The voltage drop across the product (and therefore not applied to the load), when the
switch output is ON. The voltage drop will vary with load current, and ideally should be
0 V.
When an object is placed in a fluid stream, a vortex will be created in the fluid on the
downstream side. This vortex is called a Karman vortex. The frequency at which the
vortices are generated is proportional to the fluid velocity, therefore it is possible to
calculate the fluid flow rate by measuring the Karman vortex frequency.
The resolution of set and display values.
If the minimum setting unit is 1 L/min, the flow can be displayed in 1 L/min units, i.e. 10,
11, 12.
The ambient humidity range within which the product will meet all published
specifications.
The ambient temperature range within which the product will meet all published
specifications.
-13-
Meaning
No.PF※※-OMO0012-D