OFFICE MACHINES , VENDING MACHINES AND AMUSEMENT MACHINES
.1 . TYPEWRITERS : CONTINUOUS OPERATION .
.2 . ADDING AND CALCULATING MACHINES AND CASH REGISTERS :
( A ) INTERFERENCE FROM MOTORS : IF POSSIBLE , THE MOTOR SHOULD OPERATE FOR A SUFFICIENT PERIOD OF TIME TO GIVE STEADY READINGS UNAFFECTED BY SWITCHING DISTURBANCES .
( B ) INTERFERENCE FROM SWITCHES : INTERMITTENT OPERATION WITH AT LEAST 30 STARTS PER MINUTE . IF 30 STARTS PER MINUTE CANNOT BE ATTAINED , THEN INTERMITTENT OPERATION WITH AS MANY STARTS PER MINUTE AS POSSIBLE IN PRACTICE MUST BE USED .
.3 . VENDING MACHINES AND AMUSEMENT MACHINES : AS .
. PROJECTORS
.1 . CINEMA PROJECTORS : TO BE TESTED IN CONTINUOUS OPERATION WITH FILM AND WITH THE LAMP SWITCHED ON .
.2 . SLIDE PROJECTORS : TO BE TESTED IN CONTINUOUS OPERATION WITHOUT SLIDES BUT WITH LAMP SWITCHED ON . THE CLICK RATE N IS DETERMINED ON A BASIS OF FOUR PICTURE-CHANGES PER MINUTE , BUT WITHOUT SLIDES .
. COFFEE GRINDERS : TO BE OPERATED WITHOUT GRINDING CHARGE .
. LAWN MOWERS : TO BE OPERATED CONTINUOUSLY WITHOUT LOAD .
. MILKING MACHINES : TO BE OPERATED CONTINUOUSLY WITHOUT VACUUM .
6.2.2 . PORTABLE TOOLS WITH ELECTRIC MOTORS
HAND-HELD TOOLS WHICH INCORPORATE VIBRATING OR SWINGING MASSES SHALL WHERE POSSIBLE BE MEASURED WITH THESE MASSES REMOVED OR DISCONNECTED UNLESS OTHERWISE STATED .
. DRILLS : TO BE OPERATED CONTINUOUSLY WITHOUT LOAD .
. SCREWDRIVERS AND IMPACT WRENCHES : AS IN .
. GRINDERS , DISC TYPE SANDERS AND POLISHERS : AS IN .
. SANDERS , OTHER THAN DISC SANDERS : AS IN .
. SAWS AND CUTTERS : AS IN .
. HAMMERS : AS IN .
. SPRAY GUNS : TO BE OPERATED CONTINUOUSLY WITHOUT ACCESSORIES AND WITH EMPTY RESERVOIR .
. SHEARS : AS IN .
. THREAD CUTTING MACHINES : AS IN .
. COMPASS SAWS FOR WOOD AND SIMILAR MATERIAL : AS IN .
. LIQUID AGITATORS ( INTERNAL VIBRATORS ) WITH AGITATORS FITTED : TO BE OPERATED CONTINUOUSLY IN THE CENTRE OF A ROUND STEEL-PLATE CONTAINER FILLED WITH WATER , THE VOLUME OF WATER BEING EQUAL TO 50 TIMES THAT OF THE AGITATOR ( VIBRATOR ) .
. IMPACT DRILLS : AS IN .
. PLANING MACHINES : AS IN .
6.2.3 . SOUND RECORDING AND REPRODUCTION EQUIPMENT
. RECORD PLAYERS : TO BE OPERATED CONTINUOUSLY WITHOUT RECORD .
. MAGNETIC RECORDERS : TO BE OPERATED CONTINUOUSLY USING A MAGNETIC RECORDING MEDIUM .
. SOUND-FILM PROJECTORS : TO BE OPERATED CONTINUOUSLY WITH FILM , THE LAMP BEING SWITCHED ON .
6.2.4 . ELECTRO-MEDICAL EQUIPMENT WITH MOTOR
PARAGRAPH 6.2.4 IS UNDER REVISION TO TAKE ACCOUNT OF CURRENT TECHNIQUES .
. DENTAL DRILLS :
( A ) CONTINUOUS INTERFERENCE FROM THE MOTOR : THE MOTOR TO