NO124986B - - Google Patents

Description

Procedure and device for carrying out statistical surveys.

The present invention relates to a

procedure for carrying out statistical

surveys, e.g. statistical quality control. The invention also relates to a device in the form of an electromagnetic recorder for carrying out the method.

In the case of statistical surveys such as

e.g. by statistical quality control stands

one faced with the task of examining a

or several dimensions or other characteristics of a collective and how these

characteristics are linked to the collective's individuals. The procedure so far has often

be a combination of observation (measurement) with appropriate measuring equipment,

recording the observation values, processing these by grouping them into classes

selected under a case-appropriate assessment, counting the number of individuals in each

class and analyzing the class distribution,

preferably in combination with recording of

a diagram, e.g. histogram.

A more advanced method of analysis

makes use of the so-called probability paper

(normal distribution paper) with record

of the collective's sum curve on this. The sum curve appears, as is well known, by successive accumulated addition of the histogram's (normal distribution) class ordinates.

The latter method has its special justification in cases where there is reason to

assume that the investigated dimension (trait) is normally distributed in the collective.

As a suitable example from the statistical quality control, a lot can be taken

precision shafts, the bearing diameter

must be checked. Up until now, it has been natural to use an indicative measurement unit

instrument (gauge) with measuring gap, in which the workpieces are placed in turn. The indicator's results in scale degrees are read and recorded in tables. After a suitable number has been measured, usually 100-1000 depending on the size of the collective, the measured values are grouped into classes and counted per class after which it is analyzed as mentioned above.

A not inconsiderable part of the time spent on the investigation is due to all the writing work that is connected to the recording of

the measurement values and arrangement and counting of

these in classes. Present invention,

aims to make this work redundant in the following way:

The normal scale of the used indicating measuring instrument is replaced by a replaceable special scale, where the measuring range in question is divided into a suitable number of classes for the survey, each of which is provided with its own class number, e.g.: 1, 2, 3... ... 8, 9, 0. During the measurement, the normal scale reading of the measuring instrument is neglected. Instead, the class number is read on the special scale that corresponds to the pointer reading, and the number is entered in the correct place on the keyboard of the electromagnetic recorder. If the pointer is on a class boundary, it is rounded alternately upwards and downwards.

By means of an appropriate connection device between the recorder's keyboard, switches, relays and electromagnetic counters, either a simple count in each individual class or a successive accumulated count of the class values is obtained as desired.

According to the invention, counting can take place by choice either simple or successively accumulated and the successive accumulation takes place by electromagnetic means with the help of relay coils, relay contacts, keyboard, switches and electromagnetic counters connected in an appropriate way, so that a touch in the keyboard e.g. . on key 7 is not only counted on this class' counter, but also on all counters belonging to "higher" classes. The last number (ie the one with the highest class number) will therefore, according to this principle, indicate the total number of individuals examined when the measurement has ended.

For further elucidation of the invention, it will be described below in more detail by means of an embodiment of an electromagnetic recorder according to the invention, and shown in the attached drawing in connection diagram.

The example shown illustrates an electromagnetic recorder consisting of four main parts, namely: the counter N, the reversing device O, the keyboard T and the relay device R. The recorder's setting for simple counting (histogram) is denoted H, while its setting for successive accumulated counting is denoted 2.

From power source 1, a fixed + pole is added either to the counter's N coils 2 (in reverse position for simple counting of the classes) or to the common point 3 of the relay coils 4 and the relay's counter impulse spring set 5 (in reverse position for successive accumulated counting of the classes). -=-When one of the keys 6 in the keyboard T is pressed with the reverser 7 in position H for easy counting, the pole will be connected via the keyboard T spring set contact to the other pole of the counter coil 2, whereby the counter is energized and goes one step. We get simple counting. With the change-over switch in position 2 for successive accumulated counting, the current source's + pole is broken from the counter coils and transferred to the common point 3 for the relays 4 counter impulse spring set 5 and coils as mentioned above. If one of the keys 6 in the keyboard T is now pressed down, e.g. no.

(7), the -coil is added both to the counter coil of the relevant class and to that of the same class

relay coil. The latter turns on and adds the coil via its spring sets to all relay coils belonging to keys with a higher class number which are thereby energized and turn on, whereby the counter impulse spring sets on all relays from and including the relevant class, in our case class 7 and above, are closed. As a result, the + pole from the aforementioned common point reaches the coils of the associated electromagnetic counters, which are energized and move one step each.

Claims (2)

1. Procedure for carrying out statistical surveys, e.g. statistical quality control where an appropriately large number of objects are checked individually by a suitable measuring instrument, characterized by the fact that its scale is divided into appropriate classes and that these are introduced during the measurements into an electromagnetic recorder for optional simple or successive accumulation. 2. Device for carrying out the method according to claim 1, which includes a keyboard, electromagnetic counters, switches and relays in a suitable number, characterized in that the switch device (0) is arranged so that it can be selected between simple counting or successive accumulated counting, since in the latter case by means of relay coils (4) and spring sets arranged in such a parallel connection that it is achieved that it is keyed in the keyboard that is turned down in addition to connecting the own counter impulse spring set (5) and thereby energizing it associated counter coil (2) also engages all the other keys' relay coils (4) with a higher class number, but only these and none with a lower class number, which in turn energize the associated counters (N) via their counter impulse sets (5).