|
Please find below a review
of the Logit Datavision supplied by Westholme
School in Blackburn.....
Cat. No. Being a school for pupils ranging
from 11 – 18 years we decided to trial the datalogger
with pupils from both ends of our age range. As Year
7 pupils were currently studying the topic ‘Changes
of State’, it seemed appropriate to use the logger
to determine the melting point of ice. The temperature
probe was inserted into a beaker packed with melting
ice and the equipment was connected to our interactive
whiteboard in the laboratory.
Pupils were immediately able to see a graphical representation
of how the temperature varied with time and, crucially,
how the temperature remained steady when it reached
0ºC. We then repeated the experiment with an ice
/ salt mixture which led to a discussion as to why we
put salt on icy roads at this time of year.
This datalogging experiment was used with all four of
our year 7 classes. All the teachers found the equipment
reliable, quick and easy to use and appreciated the
visual impact of the graphs obtained. It was so much
better than viewing the liquid level on a thermometer.
We liked the way the timescale axis, on Autolog, automatically
adjusted to the amount of data fed into the logger.
There was no need to set any scale before starting to
log. This is obviously very useful when you don’t
know exactly how long your experiment is going to take.
The sixth form were then asked to use the equipment
to determine the enthalpy change for the reaction between
zinc and copper sulphate by finding the temperature
rise (?T) during the reaction. In this practical the
equipment was used by the pupils themselves. They commented
on the smart, compact size of the logger and particularly
liked the screen, finding it similar to a graphical
calculator. Its games console appearance appealed to
the pupils.
The graph of temperature against time showed clear grid
lines that allowed our A-level pupils to determine ?T
with precision. Our current equipment provides a chart
with no gridlines at all.
The pupils enjoyed using the datalogger and were able
to take it back to their workstation as its use wasn’t
restricted to being linked to a computer.The downloading
of the remote datalogging was simple and quick to perform,
allowing the pupils to easily print out a graph for
their notes.
We would love to invest in several of these dataloggers
as they are pupil friendly, reliable and very easy to
use. They enhanced our teaching, and for pupils, provided
a quick but accurate feedback on the data collected.
We certainly enjoyed the chance to trial this equipment
and hope that our review of it will prove useful to
other science departments.
Mrs
G Bergman |
Mrs
Lesley Haworth |
Head of Science |
Senior Science
Technician |
Cat. No.
We trialled the equipment with a group
of able year 10 students, one of whom has described
the activities below. The work fitted in very well with
the physics topics PD1 Waves, and PD5 Application of
Physics, in the OCR 1977 (syllabus B) course. It enabled
us to demonstrate clearly how data can be transmitted
using optical fibres and we invited the students to
suggest further investigations for which the equipment
could be used.
We
used a variety of analogue sources to 'drive' the input,
including a signal generator, radio, old record player
and others, but we found the most fun was an MP3 player,
as we got to choose the sounds we played.
Having set up the equipment, we first
connected headphones, which we later changed for a small
speaker. To get more output, we adapted a PC speaker
set. The sound was perfect, but we did notice that it
was best to turn down the MP3 a little, and increase
the output volume as this reduced distortion.
We wanted to look at the output of
the device a little more closely, so we added an oscilloscope
to follow the trace. We improved this again by using
a software oscilloscope which used the sound card of
a laptop, which we then fed through a projector so the
whole group could watch.
We even shone a laser pen directly
down the fibre. This gave a very loud signal, which
gave an excellent sine wave on the oscilloscope. We
thought of connecting the oscilloscope at other points
of the circuit, but thought we might damage it. We were
now ready to do some experiments. The first thing we
did was to disconnect the fibre optic connection to
the transmit circuit. To our surprise, we found that
it was possible to move it some way from the LEDs, and
still get a good signal. This enabled us to investigate
the transmission of various materials. We found that
the signal was lost completely using a single sheet
of card, whereas a sheet of tracing paper made the signal
quieter. We also thought of using a glass chamber which
we could fill with gas, and see what effect that might
have. We could also use it to see how foggy it was.
(Someone wondered if it might be possible to make a
cable to transmit higher energy electromagnetic waves,
but we decided to leave that for now).
Covering
one of the LEDs, we lined the circuit board up on a
protractor, with the fibre optic cable in a clamp. Using
this set up, it was possible to investigate what angle
we could align the cable to the diode, and still get
a signal. We decided it may be interesting to investigate
if there were other coloured LEDs used in fibre optics.
The gap in the light path also let
us test other fibres. We saw that we could use different
glass fibres, and other materials to complete the gap.
There were a whole range of experiments
that we did in class for light and sound which we could
now make much more interesting. Now instead of just
shining a ray of light, we could transmit a signal (and
listen to our favourite music at the same time - all
in the name of science, of course!). We repeated the
diffraction experiments using a glass block. Someone
wondered if, since the light had travelled more slowly
through the block, we might see a delay between the
light through the glass, and a beam which had not gone
through the block. We decided the effect would probably
be too small to show with the equipment we had.
We all decide that the equipment was
great fun. Being able to transmit data as light, and
using a very coherent beam gave a number of classical
experiments a new and exciting twist.
Dr Alan P Glaze
Regents Park Community College |