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User Manual EE741 Inline Flow Sensor for Compressed Air and Gases
3.2 Functions
3.2.1 General
Maximum consumption value on the display
The consumption value on the display is limited at 999 999 999.0 m
3
. For value above this, the
display shows “LCD maximum”, while internally the consumption is metered normally up the
maximum value of 3.4 * 10
38
m
3
. Values above 999 999 999.0 m
3
Product Configurator Software.
Setting the Standard Conditions
The standard volume flow calculation is based on the standard conditions stored in the EE741
sensing unit. The factory setting for the standard conditions complies with DIN 1343:
P
0
= 1013.25 mbar, t
0
= 0 °C
The standard conditions can be changed via display menu, via EE-PCS Product Configurator
Low Flow Cut-Off
Very small (insignificant) flow values can be suppressed by setting a shutdown threshold.
Measured values below the shutdown threshold have no effect on the output signal,
display and consumption meter.
The minimum shutdown value can be set in m³/h or ft³/min.
3.2.2 Analogue Output
Current Output (OUT 1)
The analogue current output (factory setting 4 - 20 mA or 0 - 20 mA) is used for the actual flow
or temperature measured values. The analogue output is freely configurable and scalable via the
display menu or the EE-PCS Product Configurator Software.
The analogue output features an error message function according to NAMUR NE43. In the
event of a faulty sensing head, the output signal will freeze at 21 mA.
Switch (Alarm) Outputs (OUT 1 and OUT 2)
The switch outputs can be set via the display menu or via the EE-PCS Product Configurator
Software. One can select between “hysteresis mode” or “window mode” as well as between
normally closed (NC) or normally open (NO) contact.
NC (normally
closed contact)
NO (normally open
contact)
Switch point
Hysteresis
t
Nm³/h
0
1
0
1
Fig. 3
Hysteresis mode
t
Nm3/h
0
1
0
1
NC (normally
closed contact)
NO (normally open
contact)
Set point high
Hysteresis
high
Hysteresis
low
Set point low
Fig. 4
Window mode
Pulse Output (OUT 2) and Consumption Meter
The EE741 flow sensor features an integrated meter with pulse output, which totalizes the
consumption of compressed air or gas.
With the display menu or the EE-PCS Product Configurator Software, the user can set:
• Pulse duration: 0.02...2 s
•
Pulse value: 0.1...1 000 m³
The pulse - pause ratio must be at least 1:2. This means that the time between pulses must be at
least twice the pulse duration.
