The most common fault in an equipment data sheet is that the basis of the figures is not stated consistently. Whether the flow rate is the rated value or the measured value, whether the water content is an average or an upper limit, whether the cleanliness is the value at the factory or the value that is guaranteed: if these are not set out clearly, the same machine can differ considerably between the data sheets of different manufacturers. When a customer actually uses a data sheet to make a decision, the comparison is not only between the figures themselves but between whether the meaning of the data can be matched.
Only figures that can be verified are written
Our data sheets carry no extrapolated values, no industry averages and no limit values that only hold under particular conditions. Every figure corresponds to a measurement result that the customer can check for himself. For an item we cannot meet, we leave it blank or state the conditions that limit it, rather than giving a number that looks complete. Blank space does not look good, but it is safer than a figure that cannot be verified.
One of the important trade-offs is the test basis. The measurement method follows every figure, because it only means something when the customer compares it with a report from their own laboratory if the format is the same. If we state the water content and the customer measures it by a different method, putting the two figures side by side means nothing, and arguing about them means nothing either. The basis is therefore just as important as the value.
| Parameter | How we state it | Test basis |
|---|---|---|
| Water content | ≤3 ppm, stated as an upper limit | GB/T 7600 |
| Gas content | ≤0.01%, stated as an upper limit | GB/T 423 |
| Breakdown voltage | ≥65 kV, stated as a lower limit | GB/T 507 |
| Cleanliness | NAS 1638 class 5 | NAS 1638 |
| Ultimate vacuum | ≤5 Pa, the level the machine can reach | Determined by the no-load pumping capability |
| Working vacuum | -0.08 ~ -0.0999 MPa | Normal operating range |
Rated values and hard upper limits are written separately
This is the layer of the data sheet that is most easily overlooked and the one most likely to cause a misunderstanding. The processing flow rate of 6000 L/h is the capacity under the rated condition, not a figure that can be reached under any condition. The water content of ≤3 ppm is an upper limit, which says that the oil after treatment does not exceed this level; it does not say that it can be achieved with any incoming oil. The ultimate vacuum of ≤5 Pa is the best level the machine can reach under ideal conditions, and it is not the same thing as the -0.08 ~ -0.0999 MPa working vacuum range used during normal operation.
If these three kinds of value are mixed in one column, the customer easily takes the best case for the everyday performance. When they are marked separately, the selection stage avoids configuring the machine to an unrealistic target, and the operating stage avoids calling the machine faulty because the reading has not reached the limit value that was advertised. Both kinds of misjudgement have occurred on site and both have cost a good deal, while setting the basis down in advance costs far less.
The influence of the environment and the operating conditions is written into the sheet
The figures also have to carry the conditions under which they hold, otherwise they are just as incomparable. Altitude affects the vacuum level and the ambient temperature affects the range in which the machine can be used. This is stated explicitly for the TYA series: the ambient temperature is -20–45 °C, and outside that range the performance changes. The temperature control range is 45–80 °C, with the upper limit brought down to 70 °C when the water content is high; if this limitation for a high water content is not written down, a customer running at 80 °C gets a different result.
There is one more note that cannot be left out: when the pressure exceeds 0.3 MPa the filter has to be cleaned and the element changed. This is a condition of use rather than a performance figure, but it bears directly on whether the machine can be run properly over a long period, so it belongs in the data sheet rather than deep in the manual, where the customer can look it up on site without having to search for it. When the conditions are clear, the maintenance action does not get missed, and the site saves a search through the documents at the moment it is needed.
Why these details are worth taking seriously
The practical benefit of stating the basis clearly shows up in two places. The first is the selection stage: the customer sets out the indicators for their oil, the test method and the treatment target and compares them item by item with our figures. What matches and what does not is then clear at a glance; where the gap is and how large it is, is clearer on paper than it is on the telephone, and the proposal is also easier to confirm internally.
The second is the delivery and the use of the machine: when the site staff can see that the water content is marked as an upper limit and not as an average, they will not judge the machine as defective because one batch reads slightly higher, nor will they relax the monitoring after one good reading. When the indicators are used as intended, the performance of the machine is not misread and the basis for judgement on site stays consistent.
There is a further significance in terms of the habits of the industry. A product page filled with figures whose source cannot be traced looks rich in parameters in the short term, and in the long term it weakens the credibility of every parameter. We would rather the table looked plainer and kept only what can be checked over; it is also less trouble for the customer to work with, and the cost of explaining things after the sale comes down as well.
The reliability of a data sheet comes from a consistent basis, not from figures that look good.