Whilst fixing the screwdriver, I
also checked the long clinometer level against my builders level, there seems to be about a quarter of a degree difference.
I am inclined to trust the clinometer as it's level seems the more sensitive of the two.
Either way, ¼° (or 15' or arc) is probably more accurate than I could reasonably expect to get from a hand held sighting with clinometer anyway.
Obviously this cannot compare with the accuracy of a good sextant and could amount to as much as 15
nautical miles inaccuracy in position, but as I am unlikely to be carrying a sextant with me in most instances it certainly out performs a Kamal or similar makeshift methods.
For map work it suffers the obvious disadvantage of not having a built in protractor like a baseplate compass. This can easily be remedied buy using a separate romer/protractor like the one shown above or even carrying a small baseplate compass as well, giving a useful back up too.
I should mention the
case, it is reasonably sturdy and lined with thin closed cell foam. It is fit for purpose if a little ugly. I can also slide my romer into it which is handy but I can see myself making a better one at some point. For now this will certainly suffice.
The Brunton instructions suggest putting the top of the compass away from the press stud to protect the mirror from breakage. I am going to assume the same precaution is wise with this one too.
So next I set off up my local
fell, I took some map bearings for features I knew I could see up there first, A mill chimney at about 3km and a church tower at just over 2km. I had figures from a car park and a trig point about a click apart so the distances vary slightly.
The car park bearings checked out exactly and to within -½°. The trig point bearings were also exact for the chimney and -½° for the church tower. Closer examination of the 25K map showed that the building has been
overwritten with the church tower symbol. I used the centre of the square as my point but I think that may be incorrect on the ground. A small church length at 2 clicks is not too bad though I guess.
On the fell I also took some bearings from the same features, and a new one too, at a point in between my two reference points and used these to get a fix on my position.
The lines crossed within 2mm on the map, again my wandering church being the furthest out, and the other two
being spot on a fence line almost exactly where I was standing.
This is by far the most accurate results I have achieved from such a test. I have never been given cause to actually doubt the accuracy of an OS map before.
All these bearings were taken using the long sights and with the compass resting on solid points. In two cases dry stone walls and a wooden gate post for the position fix.
Hand held bearings were made a little more difficult by the hunting of the
needle, but not impossible. For hand held readings you can brace the compass at your waist and sight using the mirror as shown in the Brunton Instruction Manual.
Something I should have mentioned is that the instructions supplied with the compass are in Chinese, so unless that isn't a problem, you will want to check out the Brunton instructions anyway. The compass is more or
less the same functionally.
As an experiment I took a star shot of Polaris from my back yard.
It wasn't easy, in fact I had to make a slight estimation as I couldn't really see the star and illuminate the level at the same time.
Although the UV led light worked well enough I don't think my eye was dark adapted enough.
The reading I got from the scale was 53° or maybe just a smidge under.
My latitude here according to the 25K OS map on Memory Map is
53°34'8"N So roughly 39 miles out on a first try. Make of that what you will.
I have an idea that might improve that, but I'll have to try that another night.
Capable of taking very accurate bearings with a little care.
Capable of measuring vertical angles.
Allows magnetic declination (or variation) to be set on the dial.
Not liquid filled meaning no more annoying air bubbles.
Inexpensive for an instrument of this quality.
No built in protractor.
Requires a bit more knowledge and skill to use to it's full potential.
Not liquid filled requiring more time for the needle to settle.
Fairly heavy and a bit bulky.
So, in conclusion: Is it good value for money? Well for me it ticks all the right boxes. Most of the "Cons" listed above do not bother me much at all, although I do wonder about the damped version which seems to be not too much more expensive. If I'd seen that before ordering this one I may have gone for
it but I'm not too worried now. On the whole I like this compass a lot.
It's not a fast compass to use and it's not something you would tramp along with in your hand, so it wouldn't suit orienteering for example. In practice I only tend to use a compass for navigation when I want to check something, and accuracy is what really counts then.
So yes, I think this is very good value at the prices available at this time.
It’s not quite my ideal compass yet, but it’s nowhere near as expensive as a prismatic compass which is a pretty close contender.