I once saw PhotoShangrila Times Square selling those in large packs at cheap price. You can check it out there...

But by using thirsty hippo or equivalent products, you do not have control on the humidity. It could be too dry or too humid. Too dry, it will dehydrate all your equipment lubrication and rubber materials. Also I read from another forumer that some humidity beads release anti-fungal 'perfume' which can cause corrosion.

Better buy a decent dry box. Just be informed that the dry box humidity meter is about +/-5% off the scale because there is no consistent calibration done. You could however borrow a hydrometer to take measurements in the first few days of using your dry box.

Gonna be costly for an accurate unit. Anyway since you are traveling silica gel will be good for your carrying case.

I think there's a specific AIPO thread section from within ShutterAsia and Photomalaysia. Go over there for user reviews and price. Last I heard from that thread, they have a pretty good customer service. When buying a dry box, two of the most important thing is the dehumidifier heating element (must be reliable) and the door sealing properties.

A lot of users neglected the door sealing properties. I must agree that a door is a door and sealing is sealing. Some 'brands' out there uses cheap and flimsy door axles. Because of this weak construction, it might fail causing the door to dismantle or not seal the whole system properly causing erratic readings on the internal hydrometer. So check that the door has a solid construction, one that won't fail and check the sealing so that all four corners of the door is properly sealed to the box when closed.

From what I know, the humidifier system has 2 components - the humidifier element and the hydrometer measurement device.

The humidifier element/unit itself has a control which is analog based. A lot of sellers prefer this one because it has been reliable while the humidifier unit with digital control has been reported to be wacky at times. The hydrometer both with analog and digital display that is usually hanged at the front door is for the purpose of measuring humidity in the box. These two systems (element and display) does not connect to each other and provide any feedback and compensation which is why some people has been commenting on the accuracy which is around +/-5%.

The humidifier with digital control consist of the element itself and the display. You set the desired humidity on the front panel and it will feedback to the element until a balance is reach. This is supposedly more convenient than playing with the analog knob and wait till it stabilize and then fine tune it until it reaches our desired environment. I bought mine from Direct Photo and the salesman had this strange reject rates with these systems (assuming what he said is real).

Errr 35%??? I thought the recommended humidity range is around 40-45%? 35% would be a little too dry for your lenses.

Ooh that one from those pet shops. I get it. I also want to get one to double check on my drybox's accuracy.

I would agree to your friend's decision to install in his R&D because too low humidity tends to cause electrostatic problems. So maybe he's trying to monitor the conditions. Sometimes air-conditioned rooms/departments tend to reduce humidity levels too and become dry. But why do you install so many of them in toilets and bedrooms? Hahaha! Maybe to check on the weather outside?

I know if humidity levels reach a certain threshold it will indicate stormy/wet weather.

Right on the spot. So you're into shoes too ya. Hehehe

Yeah back to the topic. But its nice. Really.

Good buy ebernie. You'll never regret it.

Yes to prevent air leakage. Be suspicious if the door when close does not align with the dimensions of the box. Some doors are slanted a bit which indicate wrong/lousy/weak door hinge.

Don't know. I put my batteries, speedlite, memory card and plastic hoods in it too. Haha! But dry box is not a new thing for me. In the electronic industry, we keep semiconductor products in dry boxes too. Thats why I put my memory card in it too. My batteries are organized in battery covers to keep them in their respective places without shorting themselves and easy for me to carry them in packs of 4.

What about the door undazztood? You mean the weak hinge and hence door falling off? Then the power?

Hahaha! Of course. I once forgot to turn on the power but it was able to maintain humidity for 8 hours. Not bad. But I'm very concern about the door. The hinge is weak and it will not provide a good seal to the box. What about yours?