What could possibly go wrong?

Our data acquisition equipment outside the Aarhus University Mars Simulator.

Our data acquisition equipment outside the Aarhus University Mars Simulator. What could possibly go wrong?

My colleague Andrew Finlayson and I made it to Denmark on Sunday and turned up at Aarhus University bright and early on Monday morning.

We set about unpacking our equipment and around four hours later the pile of  apparatus you see above was pretty much working.

Looking at the scene, my first thought was, and is:

What could possibly go wrong?

But I am not asking in a sarcastic tone: I want to know the answer!

And I want a list! That way I can go down the list and think in advance how to avoid that possibility and what to do if I can’t.

So Monday was a good day because none of the major things which could go wrong, did go wrong. In the afternoon we lowered the pressure until it was equivalent to a height of 8 kilometres altitude and most of the equipment seemed to cope.

Tuesday was not so good. We spent the morning understanding the effect of air circulation within the chamber. Fortunately I had anticipated this might be a problem* and brought two fans with me that we could place inside the chamber. (See the pictures below).

And just when we thought we had sorted out the temperature control – the laser in our our laser hygrometer broke. This is kind of thing which is difficult to plan for. But we did have a plan!

My colleague Tom Gardiner was planning to join us tomorrow morning and by chance a new laser module had been delivered to NPL last week and he will be able to bring it with him.

So with luck – and it will require some – we should be back up and running tomorrow afternoon.

Anyway I must get to bed now – I need to be bright and alert in the morning. But below are a few pictures of our adventure.

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*Actually it was my wife who anticipated it – but I listened to her and took her advice!

Pictures 

Installing Equipment in the Aarhus University Mars SImulator

Installing Equipment in the Aarhus University Mars Simulator. The experimental section of the pressure vessel slides out on rails to allow access to the equipment.

Installing Equipment in the Aarhus University Mars SImulator

Installing Equipment in the Aarhus University Mars Simulator. Here Jens Jacobson and Jon Merrison from Aarhus University are installing a barrier to restrict air flow in the experimental section

Installing Equipment in the Aarhus University Mars SImulator

Installing Equipment in the Aarhus University Mars Simulator. My colleague Andrew Finlayson is just adjusting a mirror on the laser hygrometer. Below it can be seen an ultrasonic anemometer from Gill Instruments which measures air flow within the chamber – both natural convective flows and those due to fans.

Installing Equipment in the Aarhus University Mars SImulator

‘Feedthroughs’ in the Aarhus University Mars Simulator. One of the major problems is how to connect electrical equipment outside the pressure chamber to sensors inside the  chamber. This is how we did it!

 

Installing Equipment in the Aarhus University Mars SImulator

Two fans for moving the air inside the environmental chamber. The tiny fan on the left can move 67 cubic metres of air per hour and makes a big difference to the uniformity of the temperature within the chamber.

Installing Equipment in the Aarhus University Mars SImulator

Graph showing temperature versus time for two sensors inside the chamber. The air is unmixed at first and the two sensors indicate temperature differences from one part of the chamber to another of more than one degree Celsius. When the fan is switched on the air is mixed and the temperature becomes uniform to with 0.05 degrees Celsius.

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One Response to “What could possibly go wrong?”

  1. iamamro Says:

    This looks fascinating – reminds me how much I miss physics.

    One should always listen to one’s better half.

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