Bulletin 172 Complete

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

3(1) Foreward

New, 4-colour cover, Sponsorship (Institution of Electrical Engineers), Continued independence

4(2) Introduction

Editorial – Safety : Funding, communication and management, Diary dates (RSC meeting, ASE Scottish Region) SSERC courses

6(4) Gas guidance – addendum

Some local Scottish Gas personnel may be mis-interpreting a requirement which we dealt with in a previous article under the sub-section Portable or movable equipment. This was the need for flexible hoses with self-sealing plug and socket-end fittings.

6(4) Electrical accident report

An electrical accident with a Radford power supply.

7(5) Hazardous live

An electricity supply is deemed to be hazardous live if it is capable of rendering an electric shock or electric bum. Sometimes the Centre is called upon to specify what constitutes hazardous live.

8(6) Explosion

We have had a report of a serious incident in a Scottish secondary school when a bottle of silicon tetrachloride exploded.

9(7) Laboratory use of domestic appliances

A recent national safety circular issued by MSF entitled “Use of Domestic Appliances in the Laboratory” and gave examples of a number of accidents and dangerous occurrences arising from laboratory use of electrical appliances of domestic pattern.

9(7) Glue guns

The Centre recently inspected a couple of imported glue guns submitted for evaluation by an educational supplier. Both were hazardous.

10(8)  Reaction rates – powdered marble and acid

A method is described which allows measurements even of extremely rapid reactions between finely powdered marble and hydrochloric acid. The method relies on the use of an internal dispenser and of datalogging software.

13(11) CSYS Chemistry Experiment using a computer – pupil material

The kinetics of the hydrolysis of (2-bromo-2-methylpropane)

Instructional material is presented as an interim measure to assist teachers to meet a new requirement in the Sixth Year Studies syllabus. This states that at least one of the prescribed practical exercises is to be carried out using datalogging and computer interfacing techniques.

18(16) Higher Grade Physics – photodiodes

This article describes practical work in support of the recently altered section on photodiodes in the Revised Higher Physics syllabus.

24(22) Autoclave review

We report on three models of laboratory autoclave and a large pressure cooker. Performance criteria are described together with test procedures. The results of such tests are summarised and recommendations on purchasing are made.

33(31) Surplus equipment offers

33(31) Trade News

Wire wrapping tools, New range of power supplies from Griffin, New power supplies from Unilab, New J J M products, impulse sensor, Orbit Tellerium, Another datalogger from Harris, Harmony software, Motion QED, Model houses, New drivers for Alpha,

Wire wrapping tools, New range of power supplies from Griffin, New power supplies from Unilab, New J J M products, impulse sensor, Orbit Tellerium, Another datalogger from Harris, Harmony software, Motion QED, Model houses, New drivers for Alpha,

Bulletin 173 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

Sponsorship – Scottish Enterprise

4(2) Introduction

Standard Grade Physics – Technical Guides: Volume 2, Acknowledgement – Jimmy Bell, SSERC courses, Saturday opening, Obituary – Mrs Diane Rogers

5(3) 1992 and all that

The Health and Safety Commission (HSC) has recently published proposals for implementing the 1989 European Community (EC) Framework Directive

5(3) BC lampholders

Although there is a significant risk of electric shock from touching the live pin of a BC lampholder, we cannot  recollect ever getting an accident report from a school on an injury resulting from this cause.

5(3) Demountable transformers

Unsafe connection to the primary winding of some models of demountable transformer such as from Irwin, and imports from Russia.

6(4) Radiant heaters

Advice to dispose of dangerous radiant heat sources.

7(5) Preventing electric shock

By considering the effects of electric current passing through the human body, standards on safe working practices have been devised. These include levels for voltage, current and capacitance defining a regime known as hazardous live. They also include specifications for protective devices such as fuses and other forms of circuit breakers.

16(14) Higher Grade Human Biology

This article describes practical work in support of the newly  introduced syllabus in Human Biology at the Higher Grade. It concentrates on applications of modern instruments and information technologies in particular, datalogging devices.

25(23) Stepper motor drive Part 1

This is the first of a series of articles on means of driving stepper motors. It discusses some general properties of sequential circuits and shows how the signals to drive a 4-phase stepper are generated by J-K flip-flops.

29(27) CSYS Chemistry – Experiment using a computer – more student material

The procedure shown here is a continuation of that given in Bulletin 172. Using datalogging and computer interfacing techniques to investigate the kinetics of the hydrolysis of (2-bromo-2-methylpropane)

32(30) Equipment Notes Digital coulombmeters

Five models of digital coulombmeter are compared and their performances contrasted with that of an older model of electrometer. The article concludes with a brief description of the use of digital coulombmeters in teaching electrostatics.

36(34) New Course Material Computer control packages

New courses in computer control for use in upper secondary and middle higher education – originating from Israel.

37(35) Technical Tips

Alpha repairs: Solenoid unit, Photodiode pin identification, Rapid vice, The ring circuit, Calibrating a xenon strobe,

38(36) Trade News

Welcome PASCO Scientific, Labfacility, Solar water pumping system, Schools’ Laboratory Equipment Company, New software from djb, Batteries, New Fluke multimeters, Telling the time, Well done, Philip Harris

40(38) Surplus equipment offers

Bulletin 174 Complete

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

3(1) Opinion

Running risks

4(2) Introduction

Sponsorship, Annual Meeting dates, Science Education, SSERC Courses, Science, technology and safety

6(4) New regulation

New leglislation needed to implement six EC (European Community) Directives on health and safety at work.

6(4) HSE enquiries

From 1st of June this year the HSE Public Enquiry Service has been centralised at the HSE’s Sheffield Information Centre.

7(5) Obsolete Griffin laser

We have had enquiries from schools concerned that their Griffin laser had failed a routine maintenance test of electrical insulation.

7(5) Gamma source storage

Here we provide an estimate of the risks arising from storage of gamma sources near to or in a classroom.

8(6) Outmoded SOED circulars

Old circulars on Lasers and Carcinogens they lack relevance or technical veracity.

9(7) Higher Grade Human Biology – – Instrumentation Part II

This is the second article in a short series describing practical work for the new Human Biology syllabus at the Higher Grade.

15(13) Standard Grade Technological Studies

The article describes a project in prothesis. A summary description is given of the development of designs for a jointed, flexible foot. This is intended to improve the performance of artificial legs. Diagrams of systems and sub-systems are included.

18(16) CSYS Chemistry – Experiment using a computer, more student material

The following notes suggest techniques for monitoring changes in pH using a pH electrode and either a Harris sensor or a pH meter interfaced to a microcomputer.

27(25) Radio receiver signals

An idea for simultaneously displaying the modulated signal, decoded signal and filtered audio output in a radio receiver.

28(26) Kynar film problems

We have found that the film can deteriorate with age through the progressive effects of repeated mechanical damage.

29(27) Strain gauges in Technological Studies – a further application

We have now built and trialled a simple circuit providing crude on – off motor control.

30(28) Higher Grade Chemistry – – chemical egg timers

An alternative to that described in the prescribed practical activities (PPAs) for Unit 5, Experiment 2, of the Higher Grade Chemistry syllabus, which uses as a method the measurement of the times taken to run the same volume of pentane and propan-2-ol out of two burettes.

32(30) Buckyballs Assembly instructions and template

We provide here a copy of a simple template designed by Professor Good. This may be reproduced, folded and taped together to produce three-dimensional models of C-60 or C-70.

34(32) Trade News

Sunclocks, Electronic rainfall gauge, Repairs: Skeletons in cupboards? Glassware fabrication and repair,

Bulletin 175 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

Sponsorship: The Schools Chip project

4(2) Introduction

Editorial: Crying Wolff? Christmas closures.

6(4) OPAX stereomicroscope – nae earth!

A problem caused by the absence of protective earthing, yet the insulation system was of the type that required an earth conductor.

6(4) Beckman 9012 – fused on the neutral

Dangerous fault found in an oscilloscope.

7(5) Practical Work with Schools Chip

This article describes the structure of Mototorola Semiconductor Materials Chip, Schools Chip 1. It discusses some practical difficulties in working with the chip and provides you with ideas for practical work.

17(15) Revised Higher Grade Chemistry – radioactivity

Practical work relevant to Unit 8 : Radioisotopes in the revised syllabus is described.

27(25) Biology and Human Biology – thermistor applications

Scottish curricular contexts for such applications are indicated. Working circuits are provided which give excellent linear responses : one for general physiological work and others of ranges for ecological and other environmental investigations.

32(30) PASCO Introductory Rotational Apparatus and Centripetal Force Accessory

Our evaluation report consists of a description of several experiments with this apparatus. These compare experimental data with values calculated by theory.

39(37) Protactinium generator problems

Several teachers have contacted us this year with problems related to the protactinium generator and half life of Pa-234 experiment. These problems have been looked into and, we think, resolved.

40(38) Sodium flame pencil substitute

As a substitute for the sodium flame pencil we recommend effervescing a sodium salt into the air entry to a Bunsen

40(38) Sodium street lamps

Advice on operating 35 W, 240 V a.c, sodium street lamps New information on operating the lamps is included.

41(39) 4 mm stackable plug repairs

Plugs that have lost their grub screw can be kept in service by soldering the lead directly to one face of the hexagonal sectioned barrel.