Why
use a data logger ?
Measuring - Recording.
When you measure with a meter you only know what happens when you are present
and you have no written record of what you have measured.
When recording you will have written results on a long period.
What
is a Data Logger ?
A data logger is best
compared to a "black box" as used on planes.
It is a small box with a large memory and measuring input circuits. Measures
are taken automatically and stored in memory. When memory is full, or earlier
if wanted, the whole memory is read by a PC and processed. It is in fact this
PC software program that produces the records in form of diagrams, lists of
measures and EXCEL files for easy reports writing.
Data logger and Old
paper chart recorders.
Since ages paper chart
recorders have been used for logging. Data loggers have tremendous advantages
against chart recorders : precision, zooms, recording security, dimension,
self powered, roughness, global costs, records ready for computer processing,
etc….With a portable PC a data logger shows even real time graphics.
How to operate a data
logger?
User friendly WINDOWS
software enables most computer users to run Configuration and Processing
procedures without any special training.
Logger configuration
or set up.
To start logging you have
first to put into the logger all instruction defining this particular run.
You can give an identification name to the results, fix logging start and
stop, define desired recording interval and some other useful specification.
Configuration is done by connecting logger to a PC with the "PC
cable" and filling in the "configuration screen". Logger is
then disconnected from PC and placed in logging position with signals to be
logged connected to logger inputs.
Logger reading or
off-load.
When logging ends, logger
is again connected to PC and all logger memory content is transferred into PC
memory.
Recordings processing
Off loaded data are shown
directly as a diagram on the screen. The diagram can be "zoomed",
displayed channels can be chosen and logged values can be displayed.
Recordings may be saved as binary files or as text files for import into
EXCEL. produce diagram and report prints.
Real time readings and
modem connectivity.
Connected to a PC, the
data logger can provide for real time readings of the logged measures. When
modem connectivity is provided the remote data logger can be down loaded from
a central office implementing an active graphic real time supervision.
How to know more about the 無og range of data logger?
The 無og data logger family is the result of a.b.i. data years long
experience acquired in data logger field. The main features aimed in this
development are miniaturization, reliability, user friendliness and price for
value.
The range covers specialized loggers ( CL200, PL300 and TL500 ) and loggers
for general application (DL100, DL400C, DL400E and FL600 ).
Specialized loggers are proposed for electricity distribution -recording
currents in cables and transformers - for water distribution - pressure and
flow recording in pipes - and for air conditioning, food industry and
storage.
Loggers for general use are recording physical parameters like temperature
pressure, flow rate, level, concentration, potentials, etc… with
transducers delivering analog signals (0-1V, 4-20mA, etc…) or digital
signals (logic states or counting pulses).
*無og Applications : to visualize 5 typical applications and two
dozen of general application ideas.
*無og Software and General
Features : to
have a summary of technical and operational features
*無og Products : to visualize each type of logger and have a
print out or of each individual data sheet. To skim through the 無og Brochure
and print it.
*無og News : to learn about the latest developed
product.
Data logger
vocabulary.
Interval : is the time space between two
recorded readings. If interval is set to 15 sec the logger will take a
measure every 15 seconds (on each recording channel) and store it in memory.
Inputs
: it differs from
logger to logger, some have voltage or current inputs other digital state or
pulse inputs. Some other loggers connect directly to temperature sensors or
current transducer clamps.
Channels
: loggers with
more than one input are called multi channel loggers ; each input corresponds
normally to a channel.
Memory
capacity : best
specified in number of stored measurements or readings. Memory has to be
shared equally by the different channels. Dynamic memory allocation means
that memory has only to share between the activated channels.
Autonomy
: A data logger
is self powered by a long life battery. So one has not to provide external
power to operate it. The autonomy, in years, depends on the battery size,
logging intensity (channel number, interval) and electronic circuits design.
In a way the autonomy of a data logger is also limited by its memory size.
Resolution
: is the smallest
possible recorded jump when the measured value varies.
Precision
: should be
understood as the total precision of the recorded value (including resolution
).
Recording duration : Total time a data logger can
record. It depends of course on memory size, interval and (active) channel
number. When recording duration is insufficient the logger memory can be
configured in FIFO, last records overwriting the oldest ones; the logger
never stops logging.
