In the age of digitalisation, one would likely say that a digital display is modern, more accurate and is, therefore, the better choice. It is state of the art after all. But is that actually the case? You cannot answer this question with a clear "yes" or "no". As so often, it depends on the application. One thing is for sure, though; the advantages of an analogue indicator are often underrated.
It is not easy to say how far back the history of the classic analogue indication goes. The first sundials, with the shadow as the pointer that moves over a scale, were already in use in antiquity from around 3500 BC. From then on, new ways of analogue displays with various scales developed, starting with the watch as a time display and ending with complex measurement quantities.
In comparison, digital displays represent a comparatively young technology. Although numerical sequences were used to visualise values before, the digital display as such was not patented until 1908, when Frank W. Wood patented the 8-segment display. In the 1960s, this display method spread with the rise of fluorescent and LED displays. And to get back to timepieces again, digital displays experienced a significant boom in the 1980s due to the 7-segment digital display in wristwatches.
Reading the clock
Today, however, the "classic" scale displays are more popular than ever. Why, one wonders now, although the answer is obvious. We are used to them and therefore are easier to read. When taking a quick look, especially from a distance, you do not have to bother reading all the individual digits or even decimal places. The position of the pointer alone is enough to process the information. This is probably why railway stations still rely on its large analogue clocks on the platforms.
Despite the advantage of fast acquisition, especially concerning the time, there are also weaknesses compared to the digital display. Without a doubt, measured values can be displayed much more accurately with a digital display than with an analogue one. A display with two or even four decimal points allows for a more precise statement than a pointer that stands or fluctuates between two scale markings.
For some measured values, however, the disadvantage can also be seen as an advantage. The often "rough" visualisation allows for a quick recognition in this case, for example, whether "everything is in the green area“. This is also possible from an oblique angle or in the dark with illuminated scales and pointers. Furthermore, this is also due to the fact that analogue indicators illustrate the measuring range spatially. The scale of an analogue indicator can be seen as the original form of the pie chart, so to speak. Not only does it display the measured value, but it also provides information about how far the value is away from zero or from the limit value range.
Recognisability of trends
An often neglected factor is the observation of the pointer movement. Based on the speed of the pointer, it is possible to estimate when a limit will be reached, i.e. how much time is left until then. An experienced machine technician, who knows his machine and the behaviour of the analogue indicator, can utilise the speed of the pointer movement, e.g. an increasing pressure, to estimate and predict when and where the pointer will stop and whether the increasing or decreasing pressure is behaving normally or abnormally. This, in turn, is all but impossible with a digital display.
Durability and availability
A final point is the issue of longevity and availability. While displays can fade after a few years, there are no problems with analogue displays in this respect. Although you can easily get a new display or spare parts for it, it is possible that the control electronics and certain interfaces then no longer fit together. This is not to be feared with analogue indicators.
In conclusion, although it depends on the application, the analogue display offers more advantages than one might initially assume. The better the analogue indicator is adapted to the application and requirements, the easier it is to use the advantages of the analogue indicator. Nowadays, analogue indicators can be configured in many different ways, which enables the visualisation of a wide range of measurement values. There are almost no limits in the design of the scale alone. Different colour, zero point alignment, scale division type and return point can make each scale an individual one – we are experts when it comes to that. On request, we can complement the indicator with an individual company logo.