I have a small 600bd/ft kiln with the Canadian version of the Nyle L53. The wet/dry and venting is computerized . (little background)
The problem I am having is the sock on the wet bulb dries out on the wet bulb probe but the sock is wet up to the probe. This takes about a week or so to happen. I can tell when this is happening when the wet bulb reading on the computer doesn't move or starts to go high. I just cut off the dry part and away we go again.
I though it was too much air so I built a box around the bulb with an adjustable door for air movement and little air or more air it doesn't matter , the sock will still dry out
Kinda got me baffled a little
The sock should be muslin...cloth baby diapers work fine, cut and folded in half so about 1" of each side is in the water. The covered bulb should be about 1" above the water. So, the sock width is about 4 to 5 inches, folded in half to give 2" on each side. Sometimes the folded sock is sewn so there is a pocket for the bulb.
You can not have too much air flow...600 fpm is ideal which is around 7 miles per hour.
The problem you are having is likely due to poor fabric. Try washing the socks and rinsing well prior to use, because some fabric has a sizing coating which makes water flow poor until washed. You also could have hard water that leaves crusty chemicals behind when the water evaporates; distilled water is best.
I think the water may be the problem because when it dries out it does have a little discolouration . I will try distilled for sure
Thanks Gene
If the water is the problem, the wick will be stiff and crusty when it dries out.
I had this issue and fixed it by feeding my wet bulb trays with softened water. I use the same water softener system for producing makeup water for our boiler, so it was nice that I already had a water softener system in place.
edit; I use wicks made by USNR / Irvington-Moore.
If the sock is a Nyle type, it looks like a long shoestring, with the majority in the water bottle. If so, keep the run from the water bottle to the very wick short, to eliminate pre-evaporation before it gets to where it covers the probe.
If the sock gets crusty, then there is too much mineralization in the water, so changing water will help. You should be able to go months before the wick crusts up.
Sock material is important, as well as water. When working correctly, you should be able to suck the entire water bottle dry before the wick dries out.
What works well for cleaning a crusty old wick, any kind of soap or softener that should be used to keep the wick working well?
I just cut the crusty part off and discard it.
It likely costs more to try to clean them than to buy or make some new ones. Use cotton diaper cloth. For accurate readings, you'd do need a clean wick. Distilled water is best. If you try to clean them, use vinegar soaking first. Then soap and water, then rinse three times in fresh water each time.
If a wick dries out during use, it needs to be replaced. But it should never dry out unless the reservoir runs dry. So, why is it drying out? The wick should cover the temperature bulb which should be about 1" above the water in the reservoir. This is close enough to keep the wick wet as it soaks up water.