Windmill Software Ltd
Windows Engineering Software

May 2006

The Newsletter for PC-Based Data Acquisition and Control
Issue 93          April 2006
--------------------ISSN 1472-0221----------------------

We hope you enjoy this issue of Montior, but should you 
wish to cancel your subscription you can do so at

* Windmill News: New pH Monitoring Units
* The origins of "pH": Update
* Windmill Notes: Any Archaeologists Using Windmill?
* DAQ News Roundup
* Excel Corner: Column Chart versus Histogram
  (or How to remove the gaps between columns)

Windmill News: New pH Monitoring Units

You can now buy a pH Monitoring unit from our on-line 
catalogue.  The new package provides 16 channels of pH 
measurement.  It comprises Windmill software, a data 
acquisition and control unit which plugs into the PC's 
USB port, and pH signal conditioning.  The pH electrodes 
connect to BNC sockets.  For more information contact 
[email protected] or see

The origins of "pH": Update

In our last issue we discussed the origins of the term 
"pH".  We were pretty confident that the H stood for 
Hydrogen but offered two options as to where the p came 
from.  The first was from the German word protenz 
meaning power, and the second was just a constant.

This prompted several of you to write with other ideas.

Dennis Long was taught over 50 years ago that the "p in 
pH" refers to Potential; as in the phrase "Hydrogen Ion 

Eduard believed that pH orginated from the Latin 
"pondus Hydrogenii", meaning "weight of Hydrogen. 

Mark Ralph plumped for the p being from the French poudre 
or power - "usually ascribed to the chemist LeChatlier".

Thank you to everyone who read the article and took the 
trouble to contact us.  To read it again go to

Windmill Notes: Any Archaeologists Using Windmill?

Caverlee Cary, an archeologist at the University of 
California, asked us whether anyone was using 
Windmill software for underwater archaeology.  

We didn't know of any, but as people can just download 
the software from the Internet we are aware of only a 
few of the uses to which people put our software.  So, 
if you are an underwater archaeologist using Windmill 
please get in touch either with us at 
[email protected] or with Caverlee Cary at 
[email protected]

DAQ News Roundup

Welcome to our roundup of the latest findings in 
data acquisition and control.  

If you would like to receive more timely DAQ news updates 
then grab our RSS newsfeed at  Read for 
information how.

3D scanner reveals action inside reactors
   Scientists can peer inside high-pressure reactors and 
   oil pipelines, to assess damage or improve efficiency, 
   thanks to a new and more accurate imaging technique. 
      The technique generates 3D images by measuring the 
   capacitance of solids, liquids and gases using a 
   magnetic field. The resulting picture shows a slice 
   of the tube at any moment. These snap shots are 
   taken many hundred times a second, and putting them 
   in sequence generates an animation of what is 
   happening inside.
   Source: New Scientist

Wearable Wireless Technology to Play Central Role in Healthcare
   The nascent European wearable wireless patient 
   monitoring markets are likely to see rapid growth 
   over the next four to five years, according to a Frost 
   & Sullivan report. Heightened awareness about the 
   benefits of remote monitoring combined with the growing 
   popularity of homecare is likely to boost the uptake of 
   wearable wireless patient monitoring systems.
   Source: Frost & Sullivan

Eagle-cam provides aerodynamic insights

   Cameras and sensors mounted on a free-flying eagle 
   may help engineers learn how to build aircraft 
   capable of similar feats of aerobatics.
     Ultimately the experiments could help engineers 
   design more aerodynamic forms of airplanes, including 
   "morphing wing" craft that could mimic the shape 
   changes of free-flying birds.
   Source: New Scientist

Excel Corner: Creating a Histogram in Excel
(or How to remove the gaps between columns)

What is the difference between a column chart and a 
histogram?  One difference is in a histogram there are 
no gaps or overlap between the columns.  The histogram 
shows the frequency of events over several categories.  
To take a people counting example: imagine you were 
recording how long people paused at a shop display.  
Your data acquisition system logs the number of people 
pausing for less than 4 seconds, between 4 and 
8 seconds, between 8 and 12 seconds, etc.  When 
plotting the histogram, the people count (frequency) 
goes up the y axis and the time categories along the 
x axis. 

The histogram shows the symmetry or skewedness of the 
data, and its distribution.  

Before 2003 Excel did not have a histogram option.  You 
had to instead adjust the gap between columns in order 
to get the appearance of a histogram.

To do this:

1. Create a column chart.
2. Right-click one of the columns.
3. Select Format Data Series and then the Options tab.
4. Set the Gap Width to 0 and click OK.

If you have Excel 2003 or later, you can use the 
Histogram tool in the Data Analysis add-in.

Further Reading
For more on charting with Excel see

For more on the Excel 2003 Histogram tool

* Copyright Windmill Software Ltd
* Reprinting permitted with this notice included
* For more articles see

We are happy for you to copy and distribute this 
newsletter, and use extracts from it on your own web site 
or publication, providing the above notice is 
included and a link back to our website is in place.

An archive of previous issues is at
and an index of articles at

Windmill Software Ltd, PO Box 58, North District Office,
Manchester, M8 8QR, UK
Telephone: +44 (0)161 833 2782
Facsimile: +44 (0)161 833 2190
E-mail: [email protected]


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Copyright Windmill Software Ltd 2006
PO Box 58, North District Office, Manchester, M8 8QR, UK.
E-mail, Tel: +44 161 833 2782
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