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Thanks to great advice from this Board, I have successfully completed the installation of my Airmar B60-20 transducer in boat. It appears to be operational (measures air temperature while sitting on the trailer in my yard). I will not have a chance to check it out on the water, however, for a while due to a shoulder injury. Meanwhile another question as arisen.
A friend of mine just installed this transducer in his boat and on its first sea trial offshore, noted that the in-hull (meaning installed in a hole in the hull) Airmar was slower to detect water temperature changes than the puck-type transducer installed on his transom. My friend wonders if his transducer might be defective, but since the Airmar is installed in the hull, I'm wondering if this isn't inherent with this type of transducer, since the hull, bilge water, etc. which are in contact with the transducer can be expected to influence its sensitivity to temperature. The advice/experience of others with knowledge on this subject would be appreciated.
__________________ I am a Marine Electronics rigger. My opinons do not reflect those of my boss or anyone but me, and I am not a shill. My answers are based on 20 years of doing it for a living, and 40 years of doing it for love. your mileage may vary.
I have a B260 mounted in a pocket (through hull, not the M260 in hull). Mine responds extremely quickly to temperature changes. You did not say what fishfinder is driving it. Some units permit an adjustment of the averaging period of the temperature readings. If yours has this capacity, it may be as simple as changing a setup menu item to shorten the averaging period. Do the readings seem accurate? Are the depth functions working normally?
The fishfinder is one of the newer Garmin combo units. I don't know the number. My own Garmin 2006C combo unit has some adjustments for the temperature log, but nothing for temperature averaging you mentioned. Good idea, though. I'll suggest that he check his manual. I hear the readings appear accurate, it just takes some time for them to duplicate those of the free-standing FF. As far as I know, depth readings are accurate. Thanks.
The retailer got with Airmar and sent resistance specs for the transducer wiring to my friend. His 'ducer failed. I understand a replacement is on its way. Now comes the hard part, removal of the old 'ducer.
It will not read the water temperature. You need a seperate connection that run's to the outside of the boat. Can't remember what it's called. The manufacture of the electronics should have what you need.
It will not read the water temperature. You need a seperate connection that run's to the outside of the boat. Can't remember what it's called. The manufacture of the electronics should have what you need.
I'm sure it will read water temps without a separate attachment.
It will not read the water temperature. You need a seperate connection that run's to the outside of the boat. Can't remember what it's called. The manufacture of the electronics should have what you need.
GERM
That is incorrect. The Airmar B60-20 transducer reads water temperature as well as depth. Mine works great.
A replacement Airmar B60-20 has been delivered to my friend and, before installation, appears to be no improvement over the original one. The electrical checks he was given to perform fail as badly on the new one as the original one. He has taken the additional step to put the new original and replacement Airmar 'ducers in a bucket of water at a known temperature (about 85 degrees F). Both came up to the known temperature (as read on his Garmin GPSMAP 498) VERY slowly, compared to a transom-type Garmin transducer he happened to have on hand. In fact, the Airmar B60-20's never quite got up to the measured temperature.
I still haven't tested mine on the water, but measuring air temperature (my boat is on a trailer), my Garmin 2006C/GSD-21 with the B60-20 Airmar 'ducer indicates temperature 2-3 degrees below my Humminbird, even though they are only a few feet apart. A test on the water of my unit will probably not happen for several days yet.
For the information of all concerned, following are the contents of an inquiry I sent to Airmar, their response and my response to their response. The saga continues. I have also sent an inquiry to Garmin from which I have not heard as of yet. I plan to test my rig on Friday and take along several of my friend's 'ducers to plug into my Garmin unit and hang over the side for more information. Here are the email contents:
My initial inquiry:
My friend and I have recently each installed B60-20
> Airmar transducers in our boats.
>
> 1) I have not had a chance to test mine on the water
> yet, but in air (on the trailer) the Airmar (with
> Garmin GPSMAP 2006C and GSD-21) indicates water
> (air) temperature 2-3 degrees cooler (Fahrenheit
> degrees) than the transom mounted Humminbird
> transducer a few feet away. Do I have a problem?
>
> 2) My friend has tested his transducer (connected to
> a Garmin GPSMAP 498) on an offshore trip and found
> the Airmar to be MUCH SLOWER (minutes slower) at
> detecting temperature changes when running at 28-30
> mph. This is compared to his Humminbird fishfinder.
> Even when trolling, the Airmar seems to detect
> changes much more slowly. Any ideas as to how to
> correct this problem?
>
> Thanks very much.
Airmar's response:
Dear Bill,
>
> Thank you for contacting AIRMAR Technology
> Corporation.
>
> Q:I have not had a chance to test mine on the water
> yet, but in air (on the trailer) the Airmar (with
> Garmin GPSMAP 2006C and GSD-21) indicates water
> (air) temperature 2-3 degrees cooler (Fahrenheit
> degrees) than the transom mounted Humminbird
> transducer a few feet away. Do I have a problem?
>
> A: there is nothing wrong with the temp if it's off
> a few degrees. Most sounder electronics have a temp
> calibration which allows you to adjust the temp as
> you wish. My suggestion would be check air or water
> temp with a thermometer and use the electronics
> display(Garmin) to calibrate as needed.
>
> Q: My friend has tested his transducer (connected to
> a Garmin GPSMAP 498) on an offshore trip and found
> the Airmar to be MUCH SLOWER (minutes slower) at
> detecting temperature changes when running at 28-30
> mph. This is compared to his Humminbird fishfinder.
> Even when trolling, the Airmar seems to detect
> changes much more slowly. Any ideas as to how to
> correct this problem?
>
> A: When a temperature change is applied, a
> thermistor takes some time to change its resistance
> to match the new temperature. In water, Airmar
> standard thermistors have a thermal time constant of
> less than 10 seconds when tested alone, about 30
> seconds when contained in a bronze housing and about
> 80 seconds in a plastic housing or insert, depending
> on the model.
My response to Airmar's response:
Thanks for responding but I don't think your answer
helps much.
1) Neither my Garmin GPSMAP 2006C nor my Humminbird
Legend 3000 Deep nor my friend's Garmin GPSMAP 498 nor
his Humminbird FF (don't know the number) has the
ability to calibrate, so your statement of
"most" having this feature is questionable. Please
ask around your office to see if there isn't a better
answer.
2) Since our transducers have bronze housings, I guess
your response indicates we should expect responses to
temperature change in the range of 30 seconds. This
is not the case, at least in my friend's case, since
he tested it offshore as I previously indicated. Does
this mean his transducer is defective? If so, can a
test be performed on its replacement before he
reinstalls it?
Today I tested my new Airmar B60-20 transducer with my Garmin 2006C/GSD-21 chartplotter/fishfinder. For comparison, I also have installed on my boat a Humminbird Legend 3000 Deep which over the years has been very reliable. I also carried along my friend's 2 B60-20's to plug into my chartplotter, just to see how the readings compared. Here's what I learned.
At the dock, I tested the water temperature with a handheld digital probe...60.4-60.6 degrees F.
My Humminbird...59.8-60.2 degrees.
My Airmar/Garmin...57.3-58.1 degrees.
My friend's brand new never installed Airmar B60-20 'ducer linked to my Garmin chartplotter/fishfinder...58.1-58.3 degrees.
My friend's new, recently removed Airmar B60-20 linked to my Garmin...58.4-58.5 degrees.
These results lead me to believe the Airmar's, linked to Garmin chartplotters, by design, read about 2 degrees less than actual water temperature.
Next, I ran a few miles downriver to a power plant outfall. All the way down river, my Garmin/Airmar read about 1.5 degrees less than my Humminbird.
At the outfall, the water temperature quickly went up to 70-71 degrees as indicated by my Humminbird. Although I stayed in this water for at least 10 minutes, the Airmar/Garmin combo never climbed to less than 5 degrees below the temperature indicated by the Humminbird. It was still VERY slowly climbing when I pulled out of the outfall.
These results indicate to me the Airmar/Garmin combination are VERY SLOW to detect temperature changes...useless for detecting temperature breaks offshore.
So, what to do?
1) Return the Airmar transducer for credit and patch the hole with fiberglass. Maybe. Not desirable to say the least.
2) Replace the Airmar with a different transducer? Maybe. I have requested Garmin comment on the ability of their similar transducer to fit the same size hole as the Airmar and accomodate our 24 degree deadrise. I am hopeful this will work out.
3) Live with an insensitive (to temperature) transducer...perhaps purchase an indepent temperature sensor. The least attractive solution. I hate paying for more than what I get.
More to come when this is resolved. Thanks for any helpful input.
i just ordered the b60 thru hull transducer to go with my Garmin 3210/5212 exchange. do you like that one or i was considering the m260 in hull. my boat is a sailfish 2660 WAC. Any advice would really help, I can still make the change since my order has not shipped yet. Also do you do install work in CT? please call me 203-856-9009
I have requested Garmin comment on the ability of their similar transducer to fit the same size hole as the Airmar and accomodate our 24 degree deadrise.[/i]
Uh, I believe Garmin transducers are made by Airmar. A question does come to mind, though: if you have a Humminbird installed that is your benchmark, what exactly is your temperature problem?
Uh, I believe Garmin transducers are made by Airmar. A question does come to mind, though: if you have a Humminbird installed that is your benchmark, what exactly is your temperature problem?
Curmudgeon,
The whole idea behind the Airmar 'ducer was a backup fishfinder with temperature. I thought Airmar was state of the art. So far, not the case, at least as far as temperature sensing goes. Thanks for your interest.
In Hull Transducer Slow to Read Temperature 
I'm sure it will read water temps without a separate attachment. 
