This article does not discuss equipment parameters. It is about where the equipment photographs in our technical articles come from and the conventions for using them. There are two reasons for setting this out clearly: first, so that a reader looking at a photograph knows it corresponds to a real machine and not to an illustration; second, because we hold ourselves to a rule of our own, that a photograph shows only what can be confirmed on site and is not used in place of a specification.
Why site photographs instead of renderings
A rendering is a picture of an ideal state: uniform in scale, consistent in colour, with every part clean. A product image has its own purpose, but it cannot answer the questions a site engineer really wants answered: at what height the valves sit on this machine, from which side the filter cartridges are withdrawn, how far the control cabinet stands from the tank, whether the pipework runs upwards or downwards. Only a real photograph can answer those.
So most of the photographs in these articles come from the workshop and from site: the arrangement of the complete machine on the frame, the buttons and the digital displays on the control cabinet panel, the installed positions of the filter elements and their housings, the position of the pump set and the coupling, and the run of the pipework. A photograph shows the machine as it was delivered, which makes it at the same time a record of the geometrical relationships that most often lead to disagreement after a machine has been handed over.
What a photograph can confirm and what it cannot
What a photograph can confirm are the spatial and the structural relationships: the relative position of the components, the width of the access route, the run of the pipework, which indicators and buttons are on the operating panel, and how much floor the equipment takes up in the building. These are the things a photograph can give direct evidence for, and they are also the parts of the articles that readers return to most often.
What a photograph cannot confirm is the parameters. The scale in the picture is unreliable: a photograph compresses depth and, because of the angle it was taken from, can make the pipework look shorter or longer than it is; the lettering on the nameplate is not legible in most photographs, so the parameters always follow the text. Where performance, accuracy and test results are concerned, a photograph is not evidence and is not used to imply anything.
A few conventions for taking and filing the photographs
First, one photograph says one thing. Trying to show the arrangement of the filtration section and the arrangement of the electrical controls in the same picture leaves neither readable, so where two pictures are needed in the same article they are split into two. Second, a photograph is taken at the time; nothing is re-shot, nothing is composited, and photographs of different machines are never passed off as the same machine. Third, the caption of a photograph states the facts that can be confirmed from it; it does not describe what the equipment cannot do, and it does not imply any effect. Fourth, the parameters and the photographs are written separately, and the parameters appear only in the text and in the tables.
There is one more point about the order in which the pictures are chosen: write down the fact to be illustrated first and then look for the photograph that can illustrate it, rather than choosing an attractive picture first and attaching a caption to it afterwards. The order looks more troublesome, but it guarantees that the picture and the text are saying the same thing.
- Relative positions in a photograph may be referred to; absolute dimensions must not be scaled off it.
- Close-ups of the nameplate and the instruments have to be legible; the parameters follow the text and the photograph serves only for comparison.
- Photographs of different models are not to be mixed, and the caption must state which model it refers to.
- A site photograph has to include the necessary working condition; it must not show only the painted and cleaned surfaces.
- Where a question raised from a photograph concerns a parameter, the answer has to be found in the specification sheet and the test records.
Besides the photographs, what else is worth recording
For a machine that has been handed over, the photographs are only part of the record. Whether the specification sheet, the delivery documents, the factory test records and the equipment number match one another is another class of content that has to be checked. Like the photographs, all of it exists so that when a problem arises on site there is something in hand to compare against, instead of relying on memory. The comparable tables and checklists in the technical articles serve the same purpose.
A photograph records what this machine looks like; the parameters record what it can do. Written separately, the two do not substitute for each other.
