WO1985003772A1

WO1985003772A1 - Testing apparatus

Info

Publication number: WO1985003772A1
Application number: PCT/GB1985/000066
Authority: WO
Inventors: Andrew Keith Oates
Original assignee: Microspan Process Controls Limited
Priority date: 1984-02-21
Filing date: 1985-02-18
Publication date: 1985-08-29
Also published as: AU3938685A; EP0207076A1; JPS61501284A; GB8404499D0

Abstract

In order to keep alert the operator of apparatus which repetitively tests components, the testing apparatus stores a desired performance of the component and tests and displays the actual performance. The tested and desired performances are compared and the apparatus decides on the acceptability of the tested performance. The operator also decides on the acceptability from the displayed performance and applies his decision to the apparatus which indicates the accuracy of the operator's decision. The operator is therefore given an indication of whether his decision is correct before he accepts or rejects the component tested.

Description

TESTING APPARATUS

This invention relates to apparatus for testing components of the generally known type which tests the performance of a component in a process, compare that performance with a desired performance and indicate whether the component has passed or failed the test. When an operator is not fully alert, it is quite possible for the operator to carry out the testing procedure and to receive a "fail" indication for that component and yet include the tested component among the batch of components which have passed the test. The present invention aims to overcome this problem by providing information of the test being carried out to the operator who will then input to the apparatus his own decision as to the acceptability of the component performance. By causing the operator to make his own decision, the apparatus will make the operator more aware of the result of the test and therefore less likely to mistake the result of the test.

The invention provides apparatus for testing a component comprising means for storing a desired performance of that component, means for testing and displaying the performance of the component, means for comparing the tested and desired performances to decide on the acceptability of the tested performance, means for receiving an operator decision as to the acceptability of the displayed performance and means for indicating the accuracy of the operator's decision. An example of the invention will now be described with reference to the accompanying Figure which is a schematic diagram of testing apparatus.

The illustrated example will be described in connection with the testing of a filter used in the sterilization of a liquid. It is important that the filter does not develop an aperture large enough to allow impurities to pass, and the filter is regularly tested for apertures of greater than a critical size by forward flow tests and bubble point tests. In the forward flow test, compressed air is applied to one side of a wetted filter. Air dissolves in the liquid wetting the filter and evaporates from the liquid on the other side of the filter, so that there will be a small flow of air througjh the filter. This flow is increased as the size of the apertures in the filter increase, so that a measurement of the size of the apertures can be made from the rate of flow of air through the filter. In the bubble point test, air under greater pressure is applied to one side of the filter until the film of liquid across an aperture is caused to burst, thus allowing a greatly increased flow of air to pass through that aperture. Bursts will occur in larger apertures before smaller apertures, and so the pressure of air at which a greatly increased passage of air through the filter occurs will indicate the maximum size of apertures in the filter.

The apparatus illustrated in the Figure has a keyboard 11 for inputting information into the apparatus and a liquid crystal display 12 and a printer 13 for outputting information. The apparatus comprises a microprocessor 14 which has a memory for storing a desired performance of one or a plurality of components and a further memory for storing a programme or a plurality of programmes which process information applied at the keyboard 11 and controls the information displayed by the display 12 and also controls the performance of the test.

For the testing of a filter as described above, measurements are taken of the air pressures on either side of the filter, and these are supplied by conduits to quick acting couplings 21 on the apparatus. Air flow is controlled by solenoid valves 22, controlled by the microprocessor 14. When the test is begun, the microprocessor 14 causes a series. of questions to be displayed on the display 12, the programme proceeding to the next question when an answer to the previous question has been inputted at the keyboard 11 and processed by the microprocessor. The operator instructs the microprocessor to perform the selected test and provides various items of reference information which may be used during the test, or subsequently, for example when charging for the performance of the test. The component to be tested is connected to the apparatus by means of the quick acting couplings 21 and when the appropriate key on the board 11 is pressed to start the test, air is applied to the component to pressurize it, through flow regulators 23. There is a low flow rate regulator through which air is initially passed, but if the pressure fails to reach a given value in a predetermined time, indicating a high volume in the testing chamber, a higher flow rate regulator is automatically connected. When the pressure reaches a desired value, the microprocessor causes the apparatus to rest, allowing the pressure to stabilise within the testing chamber.

After the stabilisation period, the pressure on one side of the wetted filter is reduced and a measure is taken of the change of pressure on the other side of the filter with regard to time. The pressure/time curve is printed out on the printer 13 and is also compared by the computer with the pressure/time relationship which is ideal for the test being carried out. The machine decides whether the tested performance is sufficiently close to the ideal performance.

At the end of the test, the microprocessor programme displays on the display 12 a question to the operator, asking him to indicate whether the performance displayed by the printer 13 is acceptable or not. The operator keys in his decision which is compared with the decision of the machine and the programme then causes the display 12 to indicate whether the operator's decision is correct. An alarm is sounded if the operator decision is incorrect so as to warn him. The programme can also be arranged to prevent release of the component from the testing apparatus until the operator has keyed in the correct decision, so that the operator will be fully aware of the correct result of the test before handling the tested component and passing it to the channel for either the accepted or rejected components.

Besides displaying the variaton of pressure with time during the testing of the component, the liquid crystaldisplay 12 indicates the pressure at all stages of operation. The printer 13 is mounted on the front face of the testing apparatus and fresh supplies of paper can be inserted from the front of the testing apparatus panel. The printer 13 displays the pressure in analogue form. The printer also prints a record of when an incorrect decision is made and also prints out the correct decision when it is agreed with the operator.

Anomalous situations may occur if there is a blockage or leak in the air connections to the testing chamber. If the variation of pressure with time is zero, as might occur if a valve connection has been left closed, the microprocessor will cause the test to be discontinued and the operator will be prompted by means of the display 12 to check the connections. Similarly, when the pressure variation is excessive, as might occur with a ruptured filter or a leak in the connections, the test is again discontinued and the operator alerted. The printer 13 will print out that a failure has occurred and give the reasons.

Although the illustrated example has been described with reference to the testing of a filter, it is clear that the apparatus can be applied to the testing of any component, using transducers to measure selected parameters of that component.

Claims

CLAIMS:

1. Apparatus for testing a component comprising means for storing a desired performance of that component, means for testing and displaying the performance of the component, means for comparing the tested and desired performances to decide on the acceptability of the tested performance, means for receiving an operator decision as to the acceptability of the displayed performance and means for indicating accuracy of the operator's decision.

2. Apparatus as claimed in claim 1 wherein said indicating means comprises an audible alarm.

3. Apparatus as claimed in claim 1 or claim 2 comprising means to prevent the release of the component from the apparatus until the operator has presented the correct decision to the receiving means.

4. Apparatus as claimed in any one of claims 1 to 3 comprising means for indicating parameters in the testing means during testing of the component.

5. Apparatus as claimed in claim 4 comprising means to record said parameters and the decisions of the operator.

6. Apparatus as claimed in any one of the preceeding claims comprising means to indicate an anomaly in the testing means.

7. Testing apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.