Just digicabi dhc80


calvinchan

New Member
Mar 23, 2008
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#1
Bought 1st one, set at 50%. After 1 week drops to 38%. Called to complain, they change 1 to 1. The 2nd set, i set at 50% also drop to 42% and stay there after 2 weeks. Room never airconed, sometimes we dry clothes in that room. What do you guys think I should do? Many Thanks.
 

ZerocoolAstra

Senior Member
Mar 13, 2008
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rainy Singapore
#2
Bought 1st one, set at 50%. After 1 week drops to 38%. Called to complain, they change 1 to 1. The 2nd set, i set at 50% also drop to 42% and stay there after 2 weeks. Room never airconed, sometimes we dry clothes in that room. What do you guys think I should do? Many Thanks.
I would not be too bothered. 42% still acceptable to me. I mean... if you look at the construction of a dry cabinet, it isn't exactly laboratory-grade or something. I am happy enough if my dry cabinet maintains the humidity within a range, rather than get too paranoid when it's a few percent off from the set point.
 

GeneKoh

New Member
Jan 17, 2008
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#3
I've been using Digicabi's DHC professional series for a while now.. Got a trusty DHC-40 for my Canon systems and recently got an additional DHC-80 when I got the NEX as a manual lens camera system...

My DHC-40 never had a problem.. Dropped from 75% to 45% (set value) and stayed there.. However, when I got my DHC-80, the day I got it, it dropped from 85% to 45%, and then continued dropping till 35%, fluctuated between 35%-60% for a while and finally settled on 45% after a day... Interestingly, this only happened with the larger DHC-80 and not my 4-year old DHC-40...

Then recently my DHC-40 broke down, and I brought it back to Tagore Lane to get it fixed under warranty (the magic of a 5-year warranty) and they replaced the whole Desiccation Unit of the dry cabinet, along with the controller PCB.. Then when I brought it back home, I noticed my DHC-40 also started swinging between under and over the set value before settling down after a day plus...

My guess is this happens when the Desiccating Unit is new and starts absorbing moisture too quickly, then the automatic controller board (which is also the power supply) at the back takes a while to sense, detect and switch off the Unit, and when moisture comes back up again, it takes a while to detect and switch the unit back on again... It takes a while to get the timing right...
 

Zeropoint

New Member
Mar 20, 2009
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#4
Never put around near direct sunlight area nor hear high RH % (highly wet) area.
For Digicabi's DHC professional series, the pre-set RH value and the final steady RH value shall be around +/-3%. Cycle will be the auto
Check the rubber on the door, any leak.
After reached the set RH value: if you open the door, the RH will shoot up and slowly it will go down to the set value or slightly below and raise up 1-to-2% RH and cycle repeat.


Bought 1st one, set at 50%. After 1 week drops to 38%. Called to complain, they change 1 to 1. The 2nd set, i set at 50% also drop to 42% and stay there after 2 weeks. Room never airconed, sometimes we dry clothes in that room. What do you guys think I should do? Many Thanks.
 

Octarine

Moderator
Staff member
Jan 3, 2008
12,492
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48
Pasir Ris
#5
Bought 1st one, set at 50%. After 1 week drops to 38%. Called to complain, they change 1 to 1. The 2nd set, i set at 50% also drop to 42% and stay there after 2 weeks. Room never airconed, sometimes we dry clothes in that room. What do you guys think I should do? Many Thanks.
You should get a 2nd hygrometer, calibrate using salt test and measure again. Whatever is in the range of about 45% +/-5% is fine, no point chasing single digit values here.
 

calvinchan

New Member
Mar 23, 2008
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#6
Still at 42% not budging. Should be ok right? I set at 50% still. Means cabi never really on??
 

Zeropoint

New Member
Mar 20, 2009
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#8
For Digicabi's DHC professional series, is a digital display(temperature and RH %) with Digital Humidity Controlled system[Pre-set RH value].
Base on the specification, For DHC Series, you can control the humidity using the LCD Hygrometer on the front panel. There is a set button which you can set the humidity level you desire and the system will work according to the settings. You are able to set precise humidity for this series.(+/- 2%)
FYI: The factory pre-set is set at 45% RH.


So if you pre-set the RH to 50% (Digital Humidity controlled system), when the dry cabinet is stablised condition: RH % value(stable) shall falls within +/- 2%
; i.e. 52% to 48%.
For me I will take 53% to 47% to consider the control device is working. Look for the agent/Manfu ....




FYI: If the RH display shows 50%, whether this value is correct .... will be in difference case?. You need to calibrate it, yearly.
10 points with difference temperatures(e.g. 25degC, 30degC, 35degC) which cost a lot of Money.
But remember RH is calculated from the two measured temperatures between the temperature (dry-bulb) and temperature in wet-bulb.
Note: calibrate using salt test and measure again is Just a agar agar method.


Note the temperature for water falls from odegC to 100degC while RH taken is 0to100%.
Temperature in low (0to15++) has very low RH while Temperature in high (85++ to 100) has very high RH%(a lot of water vapour, like streaming water...)
 

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Octarine

Moderator
Staff member
Jan 3, 2008
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Pasir Ris
#9
Note the temperature for water falls from odegC to 100degC while RH taken is 0to100%.
Temperature in low (0to15++) has very low RH while Temperature in high (85++ to 100) has very high RH%(a lot of water vapour, like streaming water...)
Please, you want to read up again about the basics and ponder about the terms absolute and relative. Your posting is very misleading.
 

ZerocoolAstra

Senior Member
Mar 13, 2008
9,522
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0
rainy Singapore
#10
Note the temperature for water falls from odegC to 100degC while RH taken is 0to100%.
Temperature in low (0to15++) has very low RH while Temperature in high (85++ to 100) has very high RH%(a lot of water vapour, like streaming water...)
Can I clarify:
You are implying that when temperature is low (e.g. 0-15 deg C), RH is also low? And similarly high temperature equates to high RH??
 

calvinchan

New Member
Mar 23, 2008
56
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#11
The title should read just bought dhc80. Was sleepy when I posted. Temp is stable at 29 degrees. I want humidity at 50%, but it keeps hovering at 42-43%.
 

Octarine

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Staff member
Jan 3, 2008
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#12
The title should read just bought dhc80. Was sleepy when I posted. Temp is stable at 29 degrees. I want humidity at 50%, but it keeps hovering at 42-43%.
The temperature cannot be influenced. It's just a reading because the value of Relative Humidity is related [hence the term] to the temperature, otherwise it's meaningless.
Your RH value is fine, stop worrying.
 

TWmilkteaTW

Senior Member
May 30, 2011
2,251
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#13
The title should read just bought dhc80. Was sleepy when I posted. Temp is stable at 29 degrees. I want humidity at 50%, but it keeps hovering at 42-43%.
If i were you. I will be cool.
Really. 42-43% is no issue. I've keep my stuff at these RH %.. Dont pull hairs just because of a few %.. :bsmilie:
 

Zeropoint

New Member
Mar 20, 2009
40
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0
#14
The title should read just bought dhc80. Was sleepy when I posted. Temp is stable at 29 degrees. I want humidity at 50%, but it keeps hovering at 42-43%.
You want RH=50%, Did you pre-set the RH to 50%?
FYI: The factory pre-set is set at 45% RH or ba ba..
I suspect that you did not make any change to the pre-set of the RH. Thus, your pre-set is still set to 45% and it keeps hovering at 42-43% which is within the specification.



==========================================
For Digicabi's DHC professional series, is a digital display(temperature and RH %) with Digital Humidity Controlled system[Pre-set RH value].
Base on the specification, For DHC Series, you can control the humidity using the LCD Hygrometer on the front panel. There is a set button which you can set the humidity level you desire and the system will work according to the settings. You are able to set precise humidity for this series.(+/- 2%)
FYI: The factory pre-set is set at 45% RH. [i.e. 47% to 43% ] or {48% to 42% worst case}
You Paid higher price for the better humidity control (Digital).

So if you pre-set the RH to 50% (Digital Humidity controlled system), when the dry cabinet is stablised condition: RH % value(stable) shall falls within +/- 2%
; i.e. 52% to 48%.
For me I will take 53% to 47% to consider the control device is working. Look for the agent/Manfu .... "Lemon" product ??? Ha Ha Ha

=====================================
/////////////////////////////////////////////////////////////////
Note:
Some brand or model is a digital display(temperature and RH %) but Analog Humidity Controlled system[Manual adjust the set RH value by turning knob-Agar Agar ].
 

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Zeropoint

New Member
Mar 20, 2009
40
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0
#15
Please, you want to read up again about the basics and ponder about the terms absolute and relative. Your posting is very misleading.
Definition: The relative humidity of an air-water mixture is defined as the ratio of the partial pressure of water vapor (H2O) in the mixture to the saturated vapor pressure of water at a prescribed temperature.



Measurement:
The humidity of an air-water vapor mixture is determined through the use of psychrometric charts if both the dry bulb temperature (T) and the wet bulb temperature (Tw) of the mixture are known.
... RH is calculated from the two measured temperatures between the temperature (dry-bulb) and temperature in wet-bulb.



Difficulty of accurate humidity measurement:
A further difficulty is that most hygrometers sense relative humidity rather than the absolute amount of water present, but relative humidity is a function of both temperature and absolute moisture content, so small temperature variations within the air in a test chamber will translate into relative humidity variations.

==============================
It's just a reading because the value of Relative Humidity is related [hence the term] to the temperature, otherwise it's meaningless.
Agreed
 

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Zeropoint

New Member
Mar 20, 2009
40
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0
#16
Can I clarify:
You are implying that when temperature is low (e.g. 0-15 deg C), RH is also low? And similarly high temperature equates to high RH??
These are extreme conditions.

That is the test climate condition for electronic products to be tested:
e.g. low temp low RH
e.g. high temp high RH [85degC 90%RH]
But now, don't know how many company/manuf(s) will tested it. ....

Ignore, if ....


Did you ever measure/monitor the temperature and RH of a control air-cond room[Cool, dry-->low RH] in Singapore with various difference temp. and a non air-cond room that is in Singapore [Hot, high RH] ? 24hr 7days 365days indoor/out-door?
 

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calvinchan

New Member
Mar 23, 2008
56
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0
#17
Temp is stable at 29 degrees. It's just that it's new and while I'm having a problem this early it might get worse later on and I won't be able to do a 1 for 1 exchange. I don't mind the humidity at 42-43%. But I've set it for 50%, so I would like to dry cabinet to perform within 5%. So should I change or not? Yes I do know how to set the humidity I want. Many thanks
 

May 11, 2008
293
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0
#18
I am assuming u got the new series that comes with controller with touch button. The so called first batch of the new controller series is not so accurate. I had mine changed 3 times, the first two over read the rh by 8%, exactly like your case. The last exchange was so called the new batch and the reading over reads by between +1% to +4%, which is acceptable for me. But i would like to state that their support is damn good. Just call them and get your controller changed, its easy to diy only a 2 min job.
 

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Mar 23, 2008
56
0
0
#19
Yay, someone who understands my problem. Thanks again.
 

bruggink

New Member
Jul 2, 2008
901
0
0
#20
Yay, someone who understands my problem. Thanks again.
I see your concern here is the accuracy of your dry-cab meter but a lot of discussion here is on the whether the final RH reading is acceptable or not.

It's simple. If you find the inaccuracy of the meter not acceptable, you have to check if you can get it replaced. Ultimately, we can give lots of suggestions but we do not bear any responsibility of your equipment. It's your own dry-cab and camera at risk.
 

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