GB2342450A

GB2342450A - Coating thickness gauge

Info

Publication number: GB2342450A
Application number: GB9903992A
Authority: GB
Inventors: Ian Carrington Sellars; Brian Leslie Williams; John James Atherton
Original assignee: Elcometer Instruments Ltd
Current assignee: Elcometer Instruments Ltd
Priority date: 1998-10-06
Filing date: 1999-02-23
Publication date: 2000-04-12
Also published as: GB9821742D0; GB9903992D0

Abstract

A coating thickness gauge with an electronic memory for storing a number of coating thickness values. The gauge is arranged to calculate a number of items of statistical information from stored coating thickness values. These items form a set. The calculated values of statistical information may be displayed on a display 4. An item to be displayed may be selected by scrolling through a sub-set of items selected from the set of all available statistical items. The user therefore need only scroll through chosen items. The order of the items in the sub-set may also be selected.

Description

COATING THICKNESS GAUGE The present invention relates to a coating thickness gauge.

Coating thickness gauges are known which include a memory for storing a number of measured coating thickness values and a processor, or the like, which enables statistical information to be calculated, for example the number of readings taken and mean, standard deviation, highest value and lowest value of those readings. Each item of statistical data may be displayed one at a time on a small screen.

The provision of statistical analysis increases the utility of coating thickness gauges.

A trend in the design of coating thickness gauges has been to reduce the number of control keys on the gauge, to simplify their operation. Gauges having only four, and even just two keys are known.

However, the incorporation of more features, for example statistical analysis, into gauges with fewer keys can lead to a problem in selecting a desired piece of information for display. This generally involves many key presses, leading to wasted time.

For example, one existing gauge allows a user to continuously scroll through a sequence of statistical data by repeated pressing of a single key. Now, it is common in the industry for gauges to provide the five different statistical functions mentioned above. It could, therefore, take five key presses for a user to display the result of a desired function. Similarly, if the user was interested in two particular functions, say average and standard deviation, as he proceeded to use the gauge he would need to press the key a total of five times every time he wished to view each of the two chosen functions. This is inconvenient, particularly as it is easy to'overshoot'a particular function when repeatedly pressing a key, resulting in yet more key presses and wasted time.

It is an object of the present invention to overcome, or at least mitigate, the abovementioned problems and to provide a coating thickness gauge which allows statistical, or other, data to be accessed more efficiently.

According to the present invention there is provided a coating thickness gauge comprising a memory for storing a plurality of coating thickness values, a means for obtaining at least two items of statistical information frorn the stored values, said items of statistical information forming a first set, and a means for displaying an item of statistical information, arranged so that the item of statistical information to be displayed may be selected by a user by scrolling through a second set of items of statistical information wherein the second set is a sub-set of the first set and the items forming the second set may be selected by the user.

Thus, a user only needs to scroll through the items of statistical information relevant to a particular job.

It is preferred that the gauge is arranged so that the user may also select the order of the items in the second set. It is also preferable that the user may scroll continuously backwards and/or forwards through the second set. This allows for even quicker and more convenient access to the available information.

The gauge is preferably provided with only four keys, it could be provided with only two keys. The information present in the second set and, when possible, their order is preferably selected by use only of the keys on the gauge.

The statistical functions performed by the gauge preferably include two or more, preferably all, of i) number; ii) mean value ; iii) standard deviation; iv) highest; v) lowest; vi) range; and vii) coefficient of variation of the readings taken.

By allowing the user to select the items in the second set, its order, and to scroll both forwards and backwards through the set a considerable amount of time can be saved. It is not necessary to cycle through'redundant'data.

The gauge may be arranged to allow the statistics function to be turned off. That is, not to display any statistical data. In this mode it would function like a conventional gauge.

The gauge may be arranged to allow information including statistical data, to be downloaded from its memory to a computer. The information to be downloaded may be selected independently of the data selected for display.

The gauge may include a programmable microchip.

In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 shows a four key coating thickness gauge according to the invention; Fig. 2 is a flow chart which shows how the keys on the gauge may be used to access statistical data from a set; and Fig. 3 is a flow chart which shows how the keys on the gauge may be used to select both the data in the set, and its order.

Referring to Fig. 1 a coating thickness gauge comprises a gauge body 1 including an integral probe 2, a four key keypad 3 and a liquid crystal display 4 of the seven segment type. Other types of display could be employed, for example a graphical display. The four keys are labelle e, +, O, andrespectively. The general construction and principes of operation of coating thickness gauges are known and will therefore not be described further. The present invention is concerned with the way in which the gauge may be programmed to enable the display of selected statistical data.

During normal operation, once the gauge has been calibrated, it is operated by placing the probe 2 adjacent a coated surface. On recognising that the probe has been so placed the gauge is arranged to blink the display and then display the thickness of the coating as measured by the probe. Each time a coating thickness reading is taken the thickness value is stored in a memory.

The gauge is arranged to compute and display upon request seven different items of statistical information derived from the stored values, namely : 1. Number of readings taken; 2. Mean value of these readings; 3. Standard deviation of these readings; 4. Highest reading taken in these readings; 5. Lowest reading taken in these readings; 6. Range of these readings; 7. Coefficient of variation of these readings.

The result of each statistical function may be displayed individually on the display 4 at the selection of the user. This is achieved by selecting a "statistic display"mode of operation, rather than anormal measurement" mode. Once in the statistical display mode the user may scroll through the results of a number of statistical functions present in a set, the"user list". The functions present in the user list may be selected by the user.

The manner in which the statistical information on the user list may be displayed is shown in detail in Fig. 2.

Referring to Fig. 2. the statistics display mode is entered from the normal measurement mode 5 by pressing either the + or-key which results in the display of either the first or last item of statistical information on the user list.

Fcr example, if the user list inclues all seven items of statistical information in the order listed above, pressing the + key will result in the number of readings taken being displayed and pressing the-key will result in the coefficient of variation being displayed.

If either of the + or-keys are held for more than five seconds then the gauge enters a calibration mode 6. The calibration of gauges is known and therefore is not described further. The five second delay avoids accidental entry into the calibration mode. Of course, different delay periods could be employed, the actual length of time involved is not critical to the invention.

If no further keys are pressed then the gauge returns to the normal measurement mode 5.

If either the + or-key is released and then pressed again whilst statistical information is being displayed then either the next or previous item of statistical information on the user list will be displayed. Thus, the user may scroll forwards or backwards through the information on the user list. This process may be repeated as desired.

The manner in which the information forming the user list may be chosen, and its order selected is described in detail in Fig. 3.

By pressing the key sequence e,-, e,-the gauge enters a mode whereby the members of the user list may be selected. The gauge displays the first item on a statistics menu, by showing the appropriate symbol for that item along with its current position on the user list, indicated by a number. If the item is not currently on the user list then no digit is shown.

The items on the statistics menu and their corresponding symbols are as follows :1. N = number of readings; 2. AvE = average (mean); 3. Std = standard deviation; 4. HI = highest reading; 5. Lo = lowest reading; 6. R = range ; 7. V = coefficient of variation.

8. Off = statistics off.

In other embodiments the items on the statistics menu and/or their corresponding symbols could differ.

The statistics off function enables the gauge to be used as a conventional gauge, without display of statistical information. This makes the gauge easier to use for those who do not require statistical information.

When the + key is pressed the displayed function is entered into the next available position on the user list, whereupon the display 4 will show the symbol for that function along with a number, indicating its position on the list.

To enter the displayed item on the user menu at the next available position the + key is pressed. Alternatively, to view the next item on the statistics menu, the minus key is pressed. Repeated presses of this key will scroll around the menu items. This process is repeated until the desired functions have been selected, the e key is then pressed to save the current user list and the gauge returns to its normal measurement mode.

When the first item on the user list is stored, then the current user list is removed and replace by a new user list.

If the + key is pressed whilst the word OFF is displayed then the statistics function will be turned off.

For example, if a user wished to store a new user list consisting of highest reading, followed by number of readings he would take the following steps:1. Press the key sequence e,-, e,-, to enter the user list selection mode.

The display will now show N, that is the first item on the statistics menu, and its intended position on the user list.

2. As the user wishes to select highest reading as the first item on the user list he must press the-key three times, to scroll down the statistical menu.

The display will now show Hl. To store this function as the first item on the user list the user must now press the + key. The display will now show HI 1. Storing this function in position 1 will delete any previously stored list.

3. The second function may now be selected. In this case this is achieved by pressing the-key three times, the display will now show N. Indicating number of readings as being intended for the second position on the user list.

This function is now stored by pressing the + key. The display will now show N2.

The e key is now pressed again to return the gauge to normal measuring mode, along the route labelle 7, on Fig. 3.

As can be seen from Fig. 2 the statistics memory may be cleared by pressing the key sequence e,-, e, +.

Allowing a gauge user to select the information on the user list, its order, and to scroll through the list in opposite directions increases the efficiency with which the gauge may be used. For example, if for a particular job a gauge operator is interested in the standard deviation of the readings taken then only this item need be entered onto the user list. The standard deviation may then be viewed by pressing either the plus or minus key once only, as compared to pressing it three times if all the items were on the user list.

The above embodiment is described by way of example only. Many variations are possible without departing from the invention. For example, the gauge could have any number of keys, more or less than four. The gauge could be provided with a separate probe. The gauge could be arranged so that it may be used and programmed by sequences of key operations other than those described.

Claims

CLAIMS 1. A coating thickness gauge comprising a memory for storing a plurality of coating thickness values, a means for obtaining at least two items of statistical information from the stored values, said items of statistical information forming a first set, and a means for displaying an item of statistical information, arranged so that the item of statistical information to be displayed may be selected by a user by scrolling through a second set of items of statistical information wherein the second set is a sub-set of the first set and the items forming the second set may be selected by the user.
2. A coating thickness gauge as claimed in clai,. 1 arranged so that the user may also select the order of the items in the second set*
3. A coating thickness gauge as claimed in either claim 1 or 2, wherein the user may scroll continuously backwards and/or forwards through the second set.
4. A coating thickness gauge as claimed in any preceding claim, wherein the gauge is provided with only four or less keys.
5. A coating thickness gauge as claimed in claim 4, with only two or less keys.
6. A coating thickness gauge as claimed in any preceding claim, wherein the information present in the second set is selected by use of keys on the gauge.
7. A coating thickness gauge as claimed in any preceding claim, wherein the items of statistical information comprise number; mean value ; standard deviation; highest; lowest ; range; and coefficient of variation of stored coating thickness values.
8. A coating thickness gauge as claimed in claim 7, wherein the items of statistical information comprise all those listed.
9. A coating thickness gauge as claimed in any preceding claim arranged so that the user may cause the instrument not to display any statistical information.
10. A coating thickness gauge as claimed in any preceding claim arranged to allow information including statistical data, to be downloaded from its memory to a computer.
11. A coating thickness gauge as claimed in claim 10, wherein the information to be downloaded may be selected independently of the data selected for display.
12. A coating thickness gauge as claimed in any preceding claim including a programmable microchip.
13. A coating thickness gauge substantially as herein described with reference to the accompanying drawings.