Tuesday, 24 November 2015

Anglo-Chinese relations

Some of you may recall that, not so long ago, I was responsible for some of the training of a group of Chinese engineers. This considerably-less-than-enterprising bunch have taken the rather-too-enterprising step of deciding to re-badge our instruments in China and pass them off as their own. This has therefore meant that they are going to undertake all the training and maintenance themselves. These are the people who didn't know what an isotope was, and now they want to maintain mass spectrometers and train people to use them. I suddenly feel profound pity for any users of our instruments in China...

On the plus side, our friends from China were at least vaguely aware of their own limitations and therefore requested training from us on maintenance. Not a bad idea, but rather inconveniently they wanted it just when we were in the middle of really, really, really struggling to make their next instrument work. So we had to halt all forward progress and spend a week pulling it apart and teaching them how to put it back together again. And re-teaching them as much as we could about how to use it.

This all happened a couple of weeks ago, and it's taken me that long to try and work out how exactly to express my utter, overwhelming despair at what they don't  know without going all technical and incomprehensible on you. I've decided the only thing to do is attempt to give you a few little snapshots of the things they asked and allow you to fill in the blanks of a whole week filled with this...


Again, and again and again. I cannot begin to fathom what it is that these people don't understand about isotopes, but once again it came as a surprise to them that one element may have more than one isotope and that there is a naturally occurring ratio between these isotopes. For every 500 atoms of oxygen with mass 16 in the world, there's one of mass 18. And this, once again, was a matter of both awe and confusion. Really. And they want to pretend that they make mass spectrometers?

Why are states of matter relevant?

Our delightful visitors wanted to know why they didn't get any results when they tried to analyse solids with our instrument. Now, I would forgive you, dear reader, for thinking that's a reasonable question. But this instrument is a gas analysis instrument. We never did get to the bottom of what exactly they'd done to try and analyse a solid with a gas analysis system - did they try and ram chunks of something through the inlet pipe? More alarmingly, this was a question they returned to more than once.

Why are two different things not the same?

We have one major competitor, and had to fend off a lot of questions about the differences between our instrument and our competitor's instrument. My favourite one remains "why is the pressure in your vacuum chamber different?" Gee, I don't know, how about because the chamber is a different size, shape and composition, containing different components, pumped by different pumps, with a different gas introduction system and measured with a different gauge? Or, more vaguely, because it's totally, completely, and in every way different. You might as well ask why I'm not the same height as my husband. I'm just not.

My vague understanding trumps your hard evidence

Our smallest, roundest visitor, who has still never introduced himself to me, professes to be an engineer. As such he stood in front of the instrument, poking part of it with a screwdriver, informing us that "this cannot seal. Design is no good". He did this while (I repeat) stood in front of the instrument. The instrument was, at that point, under vacuum, and recording a pressure of 10e-7 mbar. (Bloody blogger won't let me format superscripts, so, in longhand, that's ten raised to the power of minus seven millibar. Or 0.0000001 millibar) For those not used to dealing with either exponents or measurements of vacuum - that's ten billion times lower pressure than the atmosphere around you. I think we can comfortably say that the instrument did indeed seal. And yet small-round remained adamant that it could not possibly work. What can you do in the face of such willful, obstinate intransigence?

Why is life not perfect?

I spent quite a long time explaining why it is impossible to detect two ions that arrive simultaneously when you have a single ion detector. That alone took a depressingly long time. I then moved on to explain that actually there will be a distribution of flight times even for ions of the same mass. (OK, I admit, this is going to get a bit technical, but bear with me).

Imagine, if you will, a time-trial race, where each runner sets off in turn, on their own, running only against the clock. The runners are all corralled together in a large pen, but none of them know when they're going to start, so they're all milling around, wandering back and forth, bending down to tie their shoelaces, until suddenly one is yelled at to "go!"  Each runner runs at exactly the same speed, but they won't all complete the course in the same time, as they will all have set off from slightly different positions, some of them will have already been walking in the right direction and so will get a head-start, whereas some of them will have been walking the wrong way, so will be slower.  If the conditions on the course change while they're running, then they may speed up or slow down slightly as well. So, even though they're all the same, there will be a spread in their race times. That's more or less what happens in our instruments, but instead of runners we have ions.

Broadly speaking, the more money you spend, the better chance you have a of getting all your ions to take the same length of time to complete the course. But I spent at least an hour attempting to justify why all the ions don't arrive within 250 picoseconds of each other. And the answer is essentially: because physics; because thermodynamics; because life.

And the response? "But wouldn't it be better if they all took the same time?" Well, yes, life would be lovely if everything was perfect. Why didn't I think of that?

Why are two different things not the same (Redux)?

We were challenged to explain why our competitor's instrument produced a mass spectrum from a sample of tea that was not the same as that obtained from our instrument. The conversation went something like this:

Us: Did you collect the data on competitor's instrument?
Them: No, they published it, and we saw that data.
Us: So, when you then tried the experiment on our instrument, did you use the same tea sample?
Them: No.
Us: OK. Well, was it at least the same type of tea.
Them: No
Us: Erm, so why would you expect the same result?
Them: ... <blank looks>

They genuinely seemed bewildered when asked why they thought two completely different samples, when analysed, should give identical results. I refer you again to the fact that these "engineers" and "scientists" are now responsible for training people to use our instruments in China. Bow your heads and weep for the future of analytical chemistry in the East...

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