Carb ice detector vs. carb temp.

[Jim Peace]

I am thinking I rather have the detector vs simply the temp.  

I am leaning towards the EDM 900 and I know I can get a carb temp input but would it not be better to know if you have actual ice forming?

Any pros and cons to either?  do some have both?

The carb ice detector is a separate item that cannot be part of the EDM correct?

 

[carusoam]

If you want to be able to run partial carb heat, the carb temp sensor is critical to have.

Carb Temp: gives a warning long before it happens and allows you to make infinite adjustment to stay on one side of the zone or the other.

Carb ice detector: doesn't seem to give info on which way to adjust the system or by how much... kind of like the automotive version of an idiot light? Great for the initial warning.  But max carb heat may not be what you want to respond with...

Can you get both?

any one is better than none.

Being fully loaded, cruising below clouds, you really would like to have at least one.  Going max carb heat limits power that you were using to maintain altitude.

End result:

• Carb temp, allows throttling the carb heat, to maximize available power, while eliminating carb ice.
• Carb ice warning, is great, but limited response is full carb heat.
• flying partial carb heat without carb temp is verboten.  Laws of physics demonstrate a fully blocked Carb is possible.

Jpi900: As far as the EDM monitoring or recording things that are on or off. Check their website for the various inputs they handle.  If they can measure landing gear up or down, expect carb ice detector on or off is pretty easy.  But, I don't see them handling on / off items on their list....

https://www.jpinstruments.com/shop/edm-900-2/

 

PP thoughts only. Not a carb ice expert.

 

Best regards,

-a-

[Hank]

I like my Carb Temp gage. It tells me whether I need to monitor closely or if all is well. It also lets me decide whether to proactively add a little bit of carb heat to get into the Safe zone. 

Having only a Carb Ice Detector (never heard of one) would be like putting in TKS and an Ice warning, and removing the OAT sensor. Wouldn't it be nice to know that a problem may be coming your way, rather than finding out after it hits the fan?

[pirate]

Definitely carb temp. Gives adavanced caution, nice to regulate. 

[Jim Peace]

3 hours ago, Hank said:

Carb Ice Detector (never heard of one) 

http://www.pilotshop.com/catalog/inpages/icedetect2.php?utm_source=google&utm_medium=cse&utm_term=10-03708&gclid=EAIaIQobChMIv6jamsnx1gIVE7nACh0G7AC5EAQYAyABEgLUUvD_BwE

 

 This type of system is much more reliable than temperature indicators which cannot compensate for temperature / moisture ratios. 

GIVES UP TO 5 MINUTES WARNING TIME by illuminating a RED visual ice warning light once ice formation occurs inside the carburetor thus providing the pilot sufficient time to apply carburetor heat before loss of engine performance.

Edited October 15, 2017 by Jim Peace

[Hank]

Interesting, Jim. But it's still all or nkthung on the carb heat. And if conditions don't improve, you'll be on and off, in and off. With a Carb Temp gage, if conditions warrant, i can pull just enough carb heat to get the temp out of the orange stripe and I'm good to go.

Sure, I still check it from time to time, but I've only used it in actual IMC a couple of times. Makes me feel good to see jt above the line anyway, though.

[carusoam]

It’s a straw man (?) argument regarding the relative humidity statement...

Sure relative humidity provides the moisture. 100% provides a lot of moisture...

The vacuum created inside the carb and evaporating fuel cause the additional drop in temperature.

The carb temp gauge visually supplies the temp range to avoid.  No math or RH knowledge required...

From a technical point of view, the seller of the ice light is trying to distract you with something that isn't right...

and their solution doesn't provide guidance for partial carb heat.

Two votes, no.. and two, against...

You probably won't find an engineer buying an ice light, when he wants a carb temp instrument...

Best regards,

-a-

 

 

[tigers2007]

With my carb'd D model I must use slight carb heat to "balance" the ROP/LOP numbers. What is the death zone for temp/humidity for all practical purposes and without referencing a huge chart? Or should I print/laminate that chart and keep it handy?


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[carusoam]

Good question, Tigers.

The answer is tied into what you have available to combat carb ice.

If you experience carb ice, the response is to use full carb heat to melt the ice.

If you are already using partial carb heat to improve fuel vaporization, and you collect carb ice, There isn't much additional carb heat that you can add to combat the ice.

This is why partial carb heat is forbidden without a carb temp indicator.

 

Looking at experience of carb ice in Mooneys and the environment it occurs in, there isn't a high probability of getting carb ice on clear dry days...

When you are flying below clouds, or in clouds, the RH is very high.  

Thermodynamics is responsible for providing the cold temperatures to freeze the available moisture.  We can get carb ice even when the OATs are pretty warm like summertime.

There isn't a chart available for reference.... it would take knowing the OAT where you are, and an RH meter measuring the air outside as well.  In comparison. It doesn't cost very much to get a carb temp indicator installed.

The crummy part of carb ice when you get it.  You can't tell if it’s carb ice or something more evil in the fuel, air or spark triad...

The nice thing about the ice detector light... you at least know what it is you are fighting...

 

PP thoughts only, not a CFI or mechanic...

Best regards,

-a-

[N6758N]

Carb heat is such a non issue on the C I think the carb temp sensor via the EDM-900 is just fine. 

[Hank]

1 hour ago, N6758N said:

Carb heat is such a non issue on the C I think the carb temp sensor via the EDM-900 is just fine. 

When I install an engine monitor, it will replace my existing Carb Temp gage and function.

[Jim Peace]

Thanks all…

i am currently in Dayton Ohio. Flew my 64C 3+50 from NJ to i19. Went to Air Force museum today for first time. Heading to sportys tomorrow am and then back to NJ. Perfect trip for a C. 

 

[MIm20c]

11 hours ago, N6758N said:

Carb heat is such a non issue on the C I think the carb temp sensor via the EDM-900 is just fine. 

I have the proper sensor installed but the 830 displays the temp as IAT vs CRB. Would changing the wires/pins (to CRB) provide additional information ie warnings if the temp fell into the icing range?

[carusoam]

JPI is pretty good with their online manuals...

might be worth a quick read...

It Is probably a paragraph long for that topic.

Best regards,

-a-

[MBDiagMan]

Both my planes have the same carb temp gauge.  I developed the habit of checking upon my descent and on downwind.  If it is not yellow, I don’t use carb heat.  This has worked well for me.  

[AlexLev]

I also am lucky to operate a plane with a carb temp gauge. I look at the gauge on descent/potential icing conditions and if it's yellow, pull carb heat on.

[Jim Peace]

Okay ....the carb temp on the JPI 900 kicks ass....

picture enclosed is at 7500 feet and running slightly richer than I would normally, still getting used to "lean find".  clear day carb heat off of course.  38 degrees in the throat I assume.  So nice to know what the heck is going on.....

I already am in the habit of using it to decide on weather or not to use carb heat for the landing, in clouds...etc.....

I pity the fool who don't have one.....(in my best Mr. T voice)

[Hank]

I love my carb temp gage, even if it is analog, in °C and on the bottom, to the left of my yoke. Gives me lots of information, and tells me when there's the possibility of creating ice in the throat so that I can make an informed decision about using carb heat or not, instead of just worrying . . . If it's in the orange stripe and I'm in visible moisture, I'll often crack it until the needle is above the stripe. One less thing on my mind!