Speaking technically,
a Data Logger is
any device that
can be used
to store data. This
includes devices such
as serial communication
systems or plug-in
boards which use
a computer as
a real time
data recording system. But
mostly, Data
Logger is considered
as a stand-alone device
that can read
various types of
electrical signals and
store the data
in internal memory
for later download
to a computer.
When choosing
a Data Logger the key
aspects to be
considered include-
1.
Input Signal -
Some data
loggers are dedicated
to a certain
input type while
others are programmable
for different types
of inputs, such
as- thermocouple, pH, pressure, sound etc.
2.
Number of
Inputs -
Data loggers are
available in both design
formats - single and multi-channel. A 32
channels data logger
is capable of
handling multiple inputs.
3.
Size
-Space
is a limitation in many applications. In
such cases, the
size of the
data logger may be
a critical selection
parameter. Opt for one
that is compact
and is suitable
for most input
types.
4.
Speed/Memory
- When
compared to real-time
data acquisition systems, data
loggers generally have
low sample rates. The
reason for this
is that data logger stores
data in internal
memory which is
limited. More memory is required for higher data rates. Therefore when
choosing one, it is
important to determine
the sample rate
and sample duration
which can be
used to calculate
the memory required. For
instance, if an application
requires sample rates
of 1/sec and
the test must
last one hour, the
data logger must
have capability to
store 3600 samples.
5.
Real time
Operation -
For some applications,
it is desirable
to display the
data being collected
in real-time on
a computer. For these
applications, it is
good to opt
for ones that
support this feature.
