[Stoves] Western Electric - rules for analysis of divergence

[Frank Shields]

Dear Crispin, and all,

It seems the Western Electric Rule (WER) is used when 1) we think we are
ready to put all the systems together and want to determine if they work
combined or 2) We want to convince (prove to) some NGO that we need money
funded into an international stove QC program so to move forward.

>From what I could understand (way over my head in many parts) is this looks
at nothing more than 'noise levels' of a system. We have enough (IMO) in
each segment of the systems to work on first before there is a reason to put
all systems together and look at the whole.  

 The small part that I look at (biomass fuel) is not even quantified for
ranges of parameters for any of the stoves developed. Moisture, particle
size and description, particle density, proximate analysis and their ranges
need to be researched per stove to market that stove for a fuel area and
compare that stove against others marketed for the same fuel criteria. That
noise level in itself is enough to make the WER pointless to look at. 

Regards

Frank

fes

 

 

  _____  

From: stoves-bounces at lists.bioenergylists.org
[mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Crispin
Pemberton-Pigott
Sent: Thursday, March 10, 2011 6:53 PM
To: Stoves
Cc: Steve Garrett
Subject: [Stoves] Western Electric - rules for analysis of divergence

 

Dear Friends

One of the pressing needs on Planet Stoves is a way to rate the performance
of test protocols. As is well known by now the lab tests used thus far, a
combination of thermal efficiency when boiling and a simmering task, have
not been able to predict field performance. This is a pretty serious failing
and has required the implementation of measures to deal with it.

Program managers and product choosers usually only have access to lab-based
water boiling tests because that is what people have concentrated on
performing, even though there is no statistically significant correlation
between the WBT lab results and field performance. Rob Baylis presented a
paper saying exactly this at ETHOS a few year ago.  It is unlikely that the
problem is the stove.

There are rules called Western Electric Rules for deciding if the
performance of a system is within specification, and in that case I am
referring to the test method as a system. If the results of the system, a
series of lab tests on a stove does not match field use, and the difference
between the evaluation and the field is large, and variable, then the use of
the Western Electric Rules might provide a means of testing the different
test methods.

http://en.wikipedia.org/wiki/Western_Electric_rules

Regards

Crispin

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