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No.PF
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-OMM0005-N
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Definition and terminology
Terms
Meaning
A
Accumulated flow
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 × 5 = 50 L.
Accumulated flow
external reset
A function to reset the accumulated flow to zero by using an external signal.
Accumulated pulse
output
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.
Analogue output
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.
Attachment
A metal part at both sides of the product to connect piping.
C
Cavitation
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.
Chattering
The problem of the switch output turning ON and OFF repeatedly around the set value
at high frequency due to the effect of pulsation.
D
Display flow range
The range of measured values that can be displayed for a product with a digital display.
F
Fluid temperature
Range of fluid temperature that can be measured by the product.
F.S.
(Full span, Full scale)
Stands for "full span" or "full scale", and indicates varied display value and 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])
H
Holding of
accumulated flow
A function to store the accumulated flow value in the product’s internal memory. The
flow value will be stored at a set time interval of either 2 or 5 minutes. When the power
supply is turned on, the stored accumulated flow value will be displayed and
accumulated flow will continue from that point.
Hysteresis
The difference between ON and OFF points used to prevent chattering. Hysteresis can
be effective in avoiding the effects of pulsation.
Hysteresis mode
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 (set value
– hysteresis value).
I
Instantaneous flow
The flow passing per unit of time. If it is 10 L/min, there is a flow of 10 L passing through
the device in 1 minute.
Internal voltage drop
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.
K
Karman vortex
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.
Key-lock function
This function prevents the set value from being changed by mishandling.
M
Measured fluid
The fluid(s) that the product can measure.
Min. setting unit
The resolution of set and display values. If the minimum setting unit is 1 L/min, the
display will change in 1 L/min steps, e.g.
10…..11…..12 L/min.
Summary of Contents for PF3W7 Series
Page 12: ...11 No PF OMM0005 N Model Indication and How to Order Metal piping...
Page 13: ...12 No PF OMM0005 N Polyvinyl chloride piping...
Page 45: ...44 No PF OMM0005 N List of output modes for fluid temperature...
Page 48: ...47 No PF OMM0005 N Example of display of sub screen...
Page 49: ...48 No PF OMM0005 N Example of display of sub screen continued...
Page 78: ...77 No PF OMM0005 N PF3W711 Vinyl chloride piping PF3W721 Vinyl chloride piping...