Bulletin 149 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Introduction

Obituary – Mr.Hugh Medine, ASE Annual Meetings, UK ASE Meeting, ASE Scottish Meeting, Cost index, Did you know, Have you read

4(2) Opinion

“Ad-hoccery makes a mockery or “Enough is Enough”

7(5) AIDS and school science

Increasingly teachers and others have been approaching us directly for advice and information on the HTLV-III virus. We have answered those enquiries to the extent of our current knowledge.

8(6) Model steam engines

Following three serious accidents in England we have been requested to provide a safety summary on model steam engines of the type used in schools to demonstrate energy conversions.

10(9) Syringe modification: anti-water pistol

One of the commonest used for syringesis that of dispensing measured volumes of liquids, particularly in Si and 52. Misuse of syringes is too tempting for many of these pupils.

11(9) Protection of ammeters

Mr Haggart, a teacher in Galashiels Academy, has sent us an ingenious solution to the problem of how to protect ammeters from the effects of an overload current.

13(11) a.c. current measurement

An addendum to the articles in Bulletin 147

15(13) Velocity of sound in air

This is an account of a way of determining the velocity of sound in air by measuring the time taken for sound to travel a set distance. The apparatus has home built elements comprising two sound activated switches and the processing circuitry required to operate a digital timer

22(20) ASE Annual Meeting

A report and trade review of the meeting in York.

Bulletin 150 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Foreword

21st anniversary edition.

6(4) Introduction

Special edition, Cover colour , Index, Specialists’ signposts, RSC offer, CLEAPSE Guides

7(5) Environmental Notes

7(5) Environmental parameters, in general & pH in particular

We deal first with the tricky business of pH measurements in natural waters.

10(8) Portable magnetic stirrers

Edinburgh Academy Science Department recently showed us a battery powered, magnetic stirrer suitable for use both in field and laboratory.

11(9) Conductivity meters

The theory of conductivity measurement is outlined briefly with advice on water sampling practice in the field. Three conductivity meters and four conductivity probes are evaluated.

16(14) Bridge circuits

Bridge networks are often used in out of balance conditions with resistive sensors. Crucial to design work is the question of linearization, a property which is shown to be dependent on a careful choice of bridge.

21(19) Active bridges

There are some who consider the active bridge to be overlooked and undervalued. Two types are shown and some indication given of their usefulness.

23(21) Applications 

There is a very side range of uses to which bridges are put in instrumentation.

23(21) Platinum film resistors 

Platinum film resistors have a wide operating range which extends from -250°C to +850°C.

14(22) Strain gauge 

The strain gauge by way of contrast operates with very small shifts in resistance.

25(23) Thermistors 

Thermistors are semiconductor devices with either a negative or a positive temperature coefficient

28(26) Interfacing 

Interfacing with active bridge circuits.

32(30) Surplus Equipment

33(31) History Notes

41(31) Index —bulletins 140 to 149

Bulletin 151 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Comment

An allegory

4(2) Introduction

Editorial policy, Data Protection Act, Microelectronics Monographs, No Comment, Surplus, For Sale

6(4) Don’t blow it!

Almost as an aside in Bulletin 148, we warned against the practice of fitting mains colour-coded cable to devices designed to operate at low voltage.

6(4) Inflammatory literature?

Recently available is a useful little leaflet from the Health and Safety Executive, entitled “Storage and Use of Highly Flammable Liquids in Educational Establishments”.

7(5) Vital capacity apparatus

A simple spirometer/vital capacity apparatus, based on two plastic containers, was described in Bulletin 130 (March, 1982). We have recently received details of an even simpler design.

8(6) Electronics Notes

Comments on ‘A.C. current measurement’

10(8) Quartz crystal oscillator

Oscillators based on the quartz crystal are commonly used to provide a stable frequency  standard. Their ubiquity, however, beguiles the fact that they are not the easiest of components to work with. In this article, a dependable circuit is given which uses such a crystal.

12(10) The block and tackle

I have, from time at sea, long marvelled at the effectiveness of a single turn round a spar or capstan. This demonstration results from that experience.

12(10) Measurement of g

An ever so simple arrangement for measuring the acceleration due to gravity

14(12) Cold light source

Microscopic creatures can often be disturbed by the heat given off by the illuminating lamp. A way of overcoming the problem is by siting the lamp remote from the  microscope and piping the light to the object via a fibre optic bundle. Such a system is called a ‘cold light source’. The construction is described below.

14(12) Jig for sharpening screwdrivers

The trick is to run the edge being sharpened along a flat stone in such a way that the shaft of the implement is held at a constant angle with the surface of the stone

15(13) Mixing of aquadag

Commercially prepared aquadag is available at low cost, but for those who are interested in preparing their own, and from enquiries we know some are, here is a pointer to the recipe.

16(14) Trade News

New Scottish company, Something new, something old, VELA, Changes of name, Changes of address, Another takeover, Expanded range, Spillages, Second—hand equipment, Parts for Torbal balances, Two—way valves, Glassblowing again –  repair of condensers, Microtechnology Inset Team

Bulletin 152 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Introduction

Summer break, Energy efficiency year, Cost index

4(2) Burning gloves

Of the laboratory gloves commonly found in the catalogues particularly the disposable types, the majority are quite flammable.

4(2) Solar cells

We have now found a possible alternative source of solar cells and have samples on order.

5(3) Digital meters

New developments in A-D converter chip and LCD display technology have led to a number of reasonably inexpensive digital student meters and multimeters corning on the school market. An evaluation of student meters is described and a survey of digital multimeters is included. The place of such meters in school science is discussed with reference to available ranges and features.

17(15) Nutrient film technique

Nutrient film technique, a method used in commercial horticulture, is suggested as a possible illustration of some techniques of applied biology at school level. A basis for a  small scale pilot system is described. Possible educational uses of the system, biological as well as technological, are suggested. Further development routes are indicated.

21(19) Lamp frame

An idea of a simple lamp frame, to provide supplementary lighting and so extend the school season for plant physiology experiments,

24(22) Trade News

Microscopes, New to us, Digital deluge?

25(23) Microelectronics Monographs

Bulletin 153 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Introduction

Editorial – Fellow farewell! “MeMo 5” Saturday opening, Erratum, Olympus microscopes,

4(2) Opinion

What do they mean?

6(4) Resource News

Primary Science, “Animals in Schools” Presentation aids for chemists, Canolfan y dechnoleg wahanol, Environmental & Conservation Resources

7(5) Glass thermometer protection

Two methods of thermometer protection are outlined; the first and more expensive option uses  brass slot cases, the second a cheap and cheerful application of heat—shrink sleeving. An earlier bulletin article on an anti-roll device is also referenced

9(7) The brachistochrone

Pupils may be surprised that the quickest means of travel between two points is not always by the shortest route.

11(9) Curie point motor

The Curie point is the transition temperature between paramagnetism and ferromagnetism.

13(11) Notes for CSYS Physics

D—A and A—D conversion.

14(12) pH meters for Standard Grade

This article outlines possible Strategies for the provision of pH measurement, particularly at 53 and S4. It includes a tabulated market survey and précis results from pH meter evaluations

24(22) Surplus Equipment

Bulletin 154 Complete

The page numbers refer to the pages in the pdf. (The numbers in brackets are those given in the actual bulletin)

3(1) Introduction

Errata, grovel gravel, Delays, fawn fawn, Festive season closure, ASE annual meeting, 1987

4(2) Resource News

CLEAPSE guides, Environmental education, Surplus, other sources, No Comment

5(3) HSE pocket cards

Two sets of useful cards: “Do you work with chemicals and other materials in educational establishments?”, and  “Guidance to cleaning staff in educational establishments”

6(4) Video equipment in science

Science teachers are encouraged to seek involvement in the selection of school video  equipment. Features which make such equipment more useful in science are outlined. An account is given of one teacher’s experience and experimentation with video microscopy.

12(10) Interface reviews

This article updates the main developments in commercial interfaces and software for education, since the review article published in Bulletin 137.

30(28) Trade News

A proper degree of loopiness, Plastic pipe cutter, “Standard Science Equipment”, Soil test kits,