T E S T I N G
Sensors
WARRANTY
www.ifm.com/nz • Ph: 0800 289 436
www.foodtechnology.co.nz 39
Density is a new case, but
OPTICAL VALVE POSITION FEEDBACK INDUCTIVE
INDICATION NETWORKING SAFETY SYSTEMS
PRESSURE FLOW LEVEL
ifm have the most comprehensive range of
industrial digital sensors and IO-Link connection
technology, available today, ex-stock NZ!
ifm technology is used globally in the most
advanced F&B factories. German quality -
supported by local engineers.
Interested to know more? Give us a call.
years
on ifm products
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FT633A
the answer seemed simple
enough. This is how the
story unfolded...
Using 2x high accuracy (+/- 0.1%)
gauge pressure (level) transmitters
mounted at a fixed height apart.
We fixed the volume. Given we
know (density=mass/volume), we
can calculate density based on the
difference between the lower and
upper pressure readings. Problem
solved, almost. Now accuracy is critical
to a successful application.
Traditionally, such a system would use
gauge pressure transmitters connected
to an analogue input card, and then to
a PLC. But we know this compounds
reading & conversion errors at each
step. Our goal was to make the system
as accurate as possible. So rather
than using conventional 4…20mA
transmitters, connected in analogue
input cards. We used IO-Link (Digital)
sensors connected to the PLC Ethernet
input via an IO-Link (Digital) Master.
Why? because an IO-Link system has
absolutely no signal conversions! In
other words, what the sensor reads
is exactly what the PLC reads.
By working with pure digital signals,
typically around 1% of errors were
removed from the system. Making our
density readings as reliable as anyone
can get from a modern process plant.
Sound interesting? Call one of our ifm
trained automation engineers, located
around the country. They are ready to
listen to your needs and offer practical,
cost effective solutions.
For more information contact ifm
0800 289 436, or see the
website www.ifm.com/nz
UNUSUAL REQUESTS
GET IFM STAFF UP IN
THE MORNING
An ifm customer asked how they could accurately measure
the density of a beverage in a large tank farm. An unusual
request, given we are normally asked to measure liquid
level and temperature in tanks.
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