How to make inexpensive meteorological equipment

[Rollo]

I have just found this in "Weather" magazine from 1976--- The barometer----A barometer has been made by stretching a piece of toy balloon across the opening of an empty jam jar. Changes in external air pressure produce movements of the diaphragm; these are magnified by a lever, the support to the fulcrum being rigidly attached to the jar by a "jubilee" clip bought from a shop selling spare parts for cars. The barometer was calibrated by comparisonto a mercury barometer. As the volume of the air enclosed in the jar is very susceptible to temperature changes, this instrument can only be used in centrally heated rooms where the temperature is kept constant during that part of the day when the barometer is likely to be read. Because of this limitation no more details are given here. There are also hints in this article on how to make a simple wind vane,windsock, rain-guage and sunshine recorder!!

[I can't believe it's not better]

DIY sunshine recorder? How do I do that?

[pottyprof]

I have just found this in "Weather" magazine from 1976--- The barometer----A barometer has been made by stretching a piece of toy balloon across the opening of an empty jam jar. Changes in external air pressure produce movements of the diaphragm; these are magnified by a lever, the support to the fulcrum being rigidly attached to the jar by a "jubilee" clip bought from a shop selling spare parts for cars. The barometer was calibrated by comparisonto a mercury barometer. As the volume of the air enclosed in the jar is very susceptible to temperature changes, this instrument can only be used in centrally heated rooms where the temperature is kept constant during that part of the day when the barometer is likely to be read. Because of this limitation no more details are given here. There are also hints in this article on how to make a simple wind vane,windsock, rain-guage and sunshine recorder!!

LMAO!!!

I built that for the Duke of Edinburgh award scheme.. 79 i think it was.. there is another one that worked using a washingup liquid bottle partially squeezed and sealed.. piece of thread sellotaped to the middle and threaded over a piece of dowelling and fastened to a pointer..

great pieces of equipment.. :lol: :lol:

[Rollo]

DIY sunshine recorder? How do I do that? The article goes on re the sunshine recorder as follows, The principal component of a Campbell-Stokes recorder is usually a glass sphere. The author used a 500 ml round bottomed flask of the sort used in any school laboratory,filled with water and with a rubber bung to keep the water from spilling. The flask is rigidly attached to the horizontal member of a wooden frame by means of a collar cut from a piece of tin and held by two screws. This horizontal member also supports a semi-circular gallery 1.25 cm wide to carry the sunshine card. Two horizontal screws on opposite ends of the gallery can rotate about a horizontal axis which coincides with a horizontal diameter of the sphere. The gallery is held in the position appropriate to the time of year by means of a washer and butterfly nut on one of the screws. The success of the instrument depends on a truly semi-circular gallery of exactly the right curvature and accurate alignment of its axis of rotation with a diameter of the sphere so as to bring the sun into focus for all times of day and for all summer and winter positions of the gallery. A preliminary experiment to find the focal length of the sphere showed that the gallery would be a little more than a foot in length, so a piece of formica well over 2 feet long and 1.25 inches wide was cut for bending in a complete circle. This was done by tying a rope with a slip knot around the formica strip and gradually pulling the rope tighter (over a period of 2 or 3 weeks) until the ends overlapped and formed a complete circle of the required curvature, and moreover retained the curvature when the rope was slackened. The gallery was cut from the middle of the strip just in case the ends had not acquired quite the same curvature as the rest of the strip. Strips of old Christmas cards were used as sunshine cards, and three pairs of short panel pins near opposite ends of the gallery keep the cards in position. One hour's sunshine can be calculated from the semi-circumference of the gallery. It is worth recording that the horizontal bar supporting the flask was originaaly too thick to allow the gallery to rise to its extreme winter position and two nicks had to be cut to allow this. If a new instrument were made, this would be avoided;but in any case a scale drawing is a useful aid to accurate construction, particularly the alignment of the axis of rotation of the gallery with a diameter of the sphere. Please note.... this is taken verbatim from the magazine and has not been attempted by this writer.

[I can't believe it's not better]

Thanks Rollo, I've saved that. It sounds quite involved, perhaps I'll just make a model one for my Tracy Island.

[I can't believe it's not better]

Here's a rather simple sunshine recorder...

Flexible photovoltaic strip, convex (i think) running a cheap quartz alarm clock. Calibrate for sunshine, using black sticky tape and a Cambell-Stokes sunshine recorder

[Verglas]

I have just found this in "Weather" magazine from 1976--- The barometer----A barometer has been made by stretching a piece of toy balloon across the opening of an empty jam jar. Changes in external air pressure produce movements of the diaphragm

I made one years ago with a wide glass vase (about 5" dia) with cling film accross the top, and a piece of basket cane glued to the centre and the rim, and a cardboard scale taped to the side with markings to see what was happening

all good fun !

[Mondy]

Thanks Rollo, I've saved that. It sounds quite involved, perhaps I'll just make a model one for my Tracy Island.

LOL :lol: I'd no idea what a Tracy island was until i googled!

Well, it appealed to me