Wednesday, October 29, 2008

Resolving my hygrostats readings - Part 2

With a doubt about its accuracy, I took my hand-held unit back to the shop for comparison. I was attended by the manager. He was surprised I thought the unit inaccurate compared to the hygrostats (both bought from them).

The sensor used is 'thin-film' technology and should be more accurate he said.
But I got all 4 hygrostats track each other within 1% and reading 9% lower from the hand-held unit, I informed.

Without fuss he had the show room unit side by side with mine. After a few minutes, the reading differences between the 2 units was 1.3%! What can I say now!

Today, I went back with my camera to repeat the tests again. This time I was attended by an executive; the results was repeatable.

After a few minutes, the readings converged to 1.5% from each other.















A bit later difference was down to 1.2%.















Waited for another 5 min, it was still 1.2%.















Well, I am satisfied now.

The hygrostats actually has an offset adjustment of +/- 9%. So reading can be set to the hand-held unit as reference.

I also learned the accuracy of hygrostats sensor do drift with time and can be affected by environmental dusts, chemical pollutants etc.

So it is advisable to check their accuracy from time to time. For a start I will check them at 3-month interval and then to 6-month interval if sensors are still good.

Finally I would recommend when buying hygrostats, choose a brand that has replacement sensors.

Another word of caution, avoid blowing into the sensor (thin film type especially) to check its sensitivity. Just wrap your palm around and the humidity should go up in quick response; or place close to a glass of ice water and humidity should drop.

Thursday, October 23, 2008

A word on electrical safety


















Did you ever get an electric shock before?

Chances are you do if you have DIY around with electrical's for a while. It's no fun!

It can be fatal too.. so don't take it lightly, especially most times we work DIY alone.

Seen birds sitting on bare electrified wires?













These birds don't get killed. Well, it's back to basics... just bare this in mind:

1. Electric current flows only when there is a closed path between 2 electric potentials.
2. People get electrocuted only when electric current pass through the body exceeds certain levels (as low as 60mA, 50Hz AC).

So if the birds have long legs, stand one on each adjacent wire (with large potential differences), it will get zap too. But having 2 legs on the same wire (same electric potential) is safe.

Take a lesson from them... the safety rules are simply:

1) Use only one hand to work with electricals. 2 hands may form closed path during accidents e.g. between live & neutral/earth.

2) Make sure your body is well insulated electrically.. i.e. not touching any metal parts that may be grounded (e.g.water pipes); not standing on wet floor bare footed, hence beware of wet shoes; stand on an insulated platform or mat etc.

3) Don't work alone if possible. Be extra careful otherwise.

With these rules I've get zap for a long time.. can't remember the last time either!

Wednesday, October 22, 2008

Do you really saves money by DIY?

Most of us like to think we save money by DIY, do we? Often I do and could also be my underlying motivation subconsciously!

However, this is a very subjective question. It very much depend on what is the undertaking and how much we know before embarking on it.

In regard to farm designs, I didn't seek the service of any consultants. Took time to read & learn from many sources, visited as many farms as I could and dialogue with many experienced farmers; question the logic and understood the rational behind with scientific principles etc. It is well worth the time and efforts, for it is the the acquired knowledge forming the foundation of the undertaking. One may not get such understandings if simply follows a consultant faithfully (or blindly).

Fair to say there are many empirical rules & rules of the thumb around. One needs to keep an open mind & regard them as hypothesis yet to be proven and time tested again. The whole subject is a live study! So my farm design do incorporate features for future experimentations as I progress onwards.

On the other hand, one could legitimately argue in favor of shortening the learning curve via engaging a consultant. Then which consultant, a typical next question?

Also if one venture out on a lone journey that can end up with expensive & irreversible mistakes! It waste more valuable time and money if not a catastrophe! So it is a very personal decision to take within one's comfort zone.

Take another example I undertook to put together my bird sound system. As an electronic engineer by training, I do feel competent enough to understand all the technicalities in depth; read through all the myths about of how good a sound system should be (so to sell you an expensive system) etc. (May be someday I'll write an ebook about it)

Indeed I did save "cash out of pocket" when I tally all the expenditures for parts and components. But when you do it for the first time, sourcing all the various parts took numerous trips. Too often the cost of finding little things far outweigh the cost of purchases - running around for hardwares in order to put them together!

So is this a case of "penny wise pound foolish"?




















Of course I could justify myself with hoards of other reasons.. the need to customize it for compactness, nothing in the market optimize for my requirements etc.

Most of it all is a sense of personal satisfaction - the most intangible part of DIY undertaking!




















The final words here is not about $ savings by DIY. If you sit and think deeper during quiet moments, there are many DIY improvements you can make to your farms! Whether it will have an immediate impact to accelerate population growth, only time can tell through experimentations.

Reducing the equipment room size?

I've visited many shop units converted into bird houses. The equipment room is typically at entrance on the ground floor to house the sound system and CCTV; sometimes even with a desk & chair or cabinet for whatever reasons. Worse are designs with a passage leading to equipment room to the rear. Shop units are about 4M wide generally, a passage way would reduce the nesting room width for the birds' comfortable turning radius of 2M - simply poor utilization of space!

On another note, how often (or long) should one be in there anyway? A cubicle shape has a corner protruding into the birds' turning space too. Besides I don't like the space it takes up anyway. If I need to monitor some cameras installed, I would rather use a wireless hub and possibly connect it up via internet someday! So I won't need space for it.

With all considerations in mind, I decide on a minimal design for the equipment room when I renovated a shop-unit birdhouse recently. The drawing illustrates a view from inside with a light curtain made of black plastic material.











External view where the steel entrance is located.











Won't it be too tight for the sound system racks?
Well, my solution is to have them housed vertically in a wall-mounted steel cabinet. Two fans (one 220V/AC & one 12VDC) are mounted below to cool the electronics continually. Power amplifiers and CD/SD player are vertically mounted such that warm air rise vertically towards exhausts at the top. Exhaust vents serves as cable inlets too.



















Switch-mode power supply is chosen to minimize heat generated within. It's voltage is adjusted to charge 2 sealed-maintainence free batteries that takes care in event of power supply interruption.



















2 fans sucks air in from external (through 2x10cm diameter wall inlets).



















P'Moo lended a hand in cutting out the 10cm fan holes.



















View of the completed set-up. Silicon rubber was used to seal any gaps along the air intake path.



















Pretty neat huh? (Only if the wirings are tided up nicely)



















There is still enough (standing) room for service of course. I'll install a service light next.

Humidifier - a swiftlet's death trap!

Have you been using this type of humidifier? If so, take note what I discovered!
















Recently, I undertook a dirty task of cleaning the humidifiers! To my astonishment, I found a dead bird within - must have been trapped there "umpty" long time ago (only feathers & skeleton left behind).

I did ever wonder of such a possibility - but again, how would a bird get in there accidentally while air is blowing out during operation? What is the probability of bird falling in during "off" period: low, right?

But then it is Murphy's law again.. "If something can go wrong, it will go wrong eventually!" It is only a matter of time.

How did I address the situation? Well, these 6-litres water bottles provided the solution!



















By cutting away the top & bottom and further cut the cylindrical body into halves (axially). Mount one over the humidifier's semi-circular handle with a self taping screw. It serves as a cover over the fan.



















In addition it also diverted the updraft of the humidifiers sideways too - quite a neat solution I reckon.

Will it guarantee no birds will be trap again? Probably not.. but surely reduce the probability much further. It must be really bad luck for the next bird to get trap inside again.

How much you trust the hygrometer? Part 1

Well, I'll kick off with a subject we may be ignorant about or have taken for granted...

We normally trust readings of instrument at hand, don't we? Better than a wild guess, right?

I have 2 household type temperature/hygrometer units purchased over time. The unit (on right) was my first purchase for over a year now. I bought the unit (on left) as it has additional external temp sensor.. useful to monitor both internal & external temp. But it never occur to compare their readings until now. Temperature readings are pretty close but a 18% difference in reading! Which would you trust?















As I am building my own humidifier controllers recently, I gathered all my other instruments together and get more surprises! I also bought a hand-held unit and several hygrostats. Put them all together I get 4 different readings! The spread is 22.5%! Wow.. which do I trust now?















The later two are instrument grade products. I bought the hand-held unit for its fast response to humidity changes (and the most expensive of course). Shall I trust it more?

Another factor that compounded the issue further, differences in reading varies over time. Question of linearity amongst them varies too!

























































My object here is to open up your mind as to what you can expect with your instruments too!

Fortunately for the moment, I can resolved the situation with the 4 hygrostats that tracks with each other within 1% over time. As for the hand-held unit, I would take it back to the shop and check its accuracy against other units.

From my experience in the electronics industry, I would only trust instrument grade products from the industry. Consumer grade product companies are too cost driven in their designs that compromise product quality (both in design & production). They may lack quality assurance in precision of the sensors used.

Lesson here is to check on the company that manufactured the hygrostats - see if they have good R&D capability.

Another DIY blog?

















Well... a few DIY blogs in swiftlet farming came to life over the past year. One had came and gone, others have evolved from novices into consultants within a relatively short time span. There is nothing wrong about it, just a manifestation there is value to knowledge in swiftlet farming. It is a money spinning biz too.... as there are many more people out there who know less!

Last week I responded to a forum er seeking opinion on 'How to choose a good consultant?'. I didn't offer the advice he seeked; just vet through his design with honest opinions. After a couple of emails exchanges he wrote;
Quote
"Thanks for your valuable advice. Finally I can find some one online that willing to share their experience and knowledge for free. There are a lot of blogger without giving you any single advice or suggestion if you are not engaged them as consultant."
Unquote

In my opinion to be a successful swiftlet farmer, one needs certain amount of "hands on" involvement. Be it improvement to its micro-environment or conduct experiments to improve nests yields - because such knowledge are hard to come by; even if you are willing to pay... are you sure the information are valid or worth the money asked? There are many myths circulating out there too!















So being a handy man is a definite plus. Better still if you have a science/technical or engineering background. But some of the best DIY practitioners I came to know are self taught without formal training. They are simply very resourceful people - learn, adapt and innovate along the way!

I'll devote space here to such creative people and my personal DIY undertakings.