ASI071MC Sensor icing up

[symmetal]

Went to take some flats for my new ASI071 Pro but the sensor iced up at around -10C. It was humid and I hadn't turned on the Anti-Dew heater so warmed it up, enabled anti-dew in Ascom driver, but it made no difference. It just iced up again. I was allowing 10 mins for the cooling. I'd only used the camera for tests on a couple of nights previously and it didn't appear to ice up though it was a dry night.

The new 071 Pro doesn't include a desiccant tube and tablets and the manual makes no mention of the desiccant tube either. The older ASI071 Cool does include the desiccant tube and tablets and the manual does include instructions.

Does anyone know if the 071 Pro version is meant to use the tube method (if so why isn't it included) or not?. 

My 2 year old ASI1600 has never suffered from icing up even on damp nights and cooled to -30C. I do have the tube from the 1600 I could use and the 071 does appear to have the access port on the side. 

Alan

[alan potts]

Sorry to hear this Alan, I have only cooled mine to zero as it was so hot here. The instructions are rubbish and in my view for another camera, at one part of it refers to an 11mm spacer which the camera does not need. I have taken a darks run and tried a couple of subs but so confused with it I have stuck it in it's box and gone back to my Canon, rather disillusioned with it. If it is something one can see would you like me to try anything for you to see if there is a bad batch as mine is only 3 weeks old.

Alan

[Dr_Ju_ju]

like the ASI1600, does it have the 4 internal 'tablets' ??, if so they may need drying out....

[symmetal]

9 hours ago, alan potts said:

Sorry to hear this Alan, I have only cooled mine to zero as it was so hot here. The instructions are rubbish and in my view for another camera, at one part of it refers to an 11mm spacer which the camera does not need. I have taken a darks run and tried a couple of subs but so confused with it I have stuck it in it's box and gone back to my Canon, rather disillusioned with it. If it is something one can see would you like me to try anything for you to see if there is a bad batch as mine is only 3 weeks old.

Alan

Thanks Alan,

Yes, the enclosed instruction booklet refers to the ASI1600 which is poor. You can get the proper full manual from Zwo's website. Thanks for the offer to help. If you have some damp weather it would help if you cooled it to say -10C with and without the sensor heater enabled in the Ascom driver to see if it does freeze up and whether the heater makes a difference . You just need to visually look at the sensor to see the ice forming so there's no need to fit the scope. With mine there was no change in the ice formation with the heater on which is odd. 

8 hours ago, Dr_Ju_ju said:

like the ASI1600, does it have the 4 internal 'tablets' ??, if so they may need drying out....

The early 1600s had the 4 tablets inside but later ones incorporated the removeable desiccant tube which is screwed into an access port in the side of the case. The ASI071 has the access port. I've used the threaded metal tube and tablets from my 1600 and fitted it to my 071 to see if it helps, (after 24 hours). If I never had the 1600 I couldn't have done anything as the 071 doesn't come with the tube and tablets. Most odd. FLO sell replacement Zwo tablets but not the tube which is needed.

On the CN forum discussions do mention using the tube so must be referring to the early 071 which did include one. Replies mentioned that on the Zwo forum Zwo recommend leaving the desiccant tube on permenantly once you have to use it.

Alan

[Dr_Ju_ju]

my ASI 1600 had both the internal & external port, but note that the tablets are not interchangeable between the internal & external, which are deeper, which I found out after mine iced-up.

[alan potts]

As much as I would like to try and help the air is very dry here, it hasn't rained for 6 weeks. It is 34 outside at the moment and sunny, I am not sure I can get down to minus 10, maybe later on or tomorrow I can give it a try, can't stay this hot forever. I will see what I can do. I am very new to this, a bit daunting if I am honest, the software is my biggest bug bare, just not use to it.

Just a thought how do you turn the heater on, I have seen a warm up routine in APT and cooling, but not noticed heater.

Alan

[symmetal]

1 hour ago, Dr_Ju_ju said:

my ASI 1600 had both the internal & external port, but note that the tablets are not interchangeable between the internal & external, which are deeper, which I found out after mine iced-up.

Ah! So it might have both. I was reluctant to open the camera up to avoid getting dust on the sensor. It seems odd leaving the internal ones in place 'full of water' and using the external ones to try and dry them out a bit. Maybe that's why the external tube has been dropped. I would have thought information on replacing the internal ones would have been mentioned somewhere again. I think the tablets FLO sells are the internal ones and from your post they are a different size to the tube ones. I'll have to get a pack from FLO to try and fix it. As it's a new camera it implies the chamber isn't very airtight anyway so won't fix it for long. 

2 hours ago, alan potts said:

As much as I would like to try and help the air is very dry here, it hasn't rained for 6 weeks. It is 34 outside at the moment and sunny, I am not sure I can get down to minus 10, maybe later on or tomorrow I can give it a try, can't stay this hot forever. I will see what I can do. I am very new to this, a bit daunting if I am honest, the software is my biggest bug bare, just not use to it.

Just a thought how do you turn the heater on, I have seen a warm up routine in APT and cooling, but not noticed heater.

Alan

No problem Alan. Actually I was a bit misleading in my post in that the anti dew heater heats the window in front the sensor to stop dew forming on the window when it's humid. The sensor chamber should be airtight so the outside humidity shouldn't make a difference to the sensor. Mine apparently isn't very airtight. If the sensor is icing up the anti dew heater on the window won't make any difference to it. You could just check to see if your sensor doesn't ice up below zero C if you are able to but don't worry if you can't reach that low a temperature.

The anti dew heater is turned on here in the Ascom driver.

Also if you need to set the Offset or USB Limit you have to tick the 'Advance' box too.

Alan

 

[symmetal]

Looking through the window it looks like there are internal desiccant tablets as shown. There are two others on the other side.

Alan

[Dr_Ju_ju]

The way I did it, was to loosen the screws around the edge, then invert the camera, i.e. sensor down, then release the screws, where the front plate will drop down.

I then laid the camera to dry out, sensor down, onto some grease proof paper, which has less fibres to get attracted by static.

But on inspection you may have to clean the sensor surface, I did, and then used Baader Wonder Fluid\cloth, both applied very sparingly & exceedingly gently.

[symmetal]

Thanks Julian. I'll order a set of tablets from FLO and see if that works.

Alan

Edited September 10, 2019 by symmetal

[Dr_Ju_ju]

I just re-vitalized mine, by popping them into a microwave oven for short bursts 1~2 mins @ full blast.....  

[symmetal]

Good idea. Worth a try. 

Alan