Making sense of the Mars H-10G refrigerant leak detector
I recently purchased a used Mars H-10G leak detector, manufacture date, October 1997.
The unit seems very interesting in that it uses high line voltage -- 120 VAC -- to power it. However, the darn thing is so sensitive. I come to find out that you need to have r11 refrigerant on hand for calibrating the device. Is this absolutely necessary? I know that r11 at atmospheric temperature is in a liquid form, and therefore, can be poured in the tiny calibration bottle that you get with the unit. But again, I am confused as to why this is necessary.
Also, there is a large-medium-small setting on there as well, which I assume is for different refrigerant types. It seems that once this unit goes off, it's difficult to get it to stop sounding the alarm. I do know that this unit is sensitive enough for 1/2 ounce loss per year, which to me is what I'd consider a very small leak.
It would be greatly appreciated if someone with extensive knowledge on this unit can come to my aid. Thanks again!
The FIRST thing you need to operate and H-10 is a dose of patience.
If you don't have that in spades, sell that thing.
If you are patient, then you will love this machine once you learn it.
You have one of the older ones, and it is a little more difficult to use.
Start with the machine in open, clean air. Turn it on, set it to small, and turn the balance dial full counter clockwise.
Give it a good 2 minutes to warm up.
Turn the balance dial clockwise until it starts to squeal and then back it down. You are looking for a good 1-2 ticks per second. THIS is the fiddly part. That is a sensitive machine in small.
Now that you have it balanced, wave the probe near the calibration bottle. You are looking for a quick squeal from the machine. If you get the squeal, turn the machine to medium or large, tweak the balance knob and start sniffing.
If you don't, turn it over and give the adjustment screw on the bottom about 1/8 turn clockwise and begin the process ALL OVER again. If that turns full CW, then replace the sensor, wind the adjustment screw full CCW and start over.
The newer H-10 PMs have an auto calibrate feature that bypasses the fiddly balance knob, but I still like being able to use it in certain situations.
Thanks for this long reply. I will say that it seems that once you get used to this unit, all will be easier. But let me ask you this: why in the heck do you need r11 to calibrate this unit? Can't I use the gas from r22? It seems to work for me, but maybe there's a reason for this. I don't have r11 on hand, this is why I ask. They supply you with a tiny bottle with a screw and hold in the center of it, but no refrigerant is in it now. You are right to say that this unit requires tons of patience.
The bottle is, basically, a calibrated leak.
There is an orifice in the top that allows a very small amount of gas out.
You can do a similar job with other sources, but it won't be quite the same.
R22 works fine for calibrating, but it obviously isn't used because it's contaminating the atmosphere, while r11 stays put at atmospheric pressure in liquid form. Maybe I'm wrong, but in any case, I would like to get a new r11 vile. Are they readily available?
Thanks for your input.
Don't know if it's R-11 or not but this is what Bacharach uses for their H-10G.
Originally Posted by roller_steve
Straight R22 will fry the sensor......
This is a very sensitive measuring device, the warm up time and other operationing instructions are critical.....
It's 12 years old and should be rebuilt.......
Aronolds Instruments used to do a great job.....
As said.....you must be "patient" with this thingy....
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Originally Posted by roller_steve
The large/small settings allow you to adjust for the size of the leak. For example if you have a large leak and you are set to small your sensitivity will be too much and you will not be able to zero in on your source.I have found it better to start on small and find the general area and then bump down to the large setting to pin point the culprit. This is done by turning the ticking down to where it is excruciatingly slow but rythmic, it is the change in the cadence of the ticking that tells you that you are getting close to the leak.Find the general area with the small setting and then zero in with the large setting.
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Turn the unit on, set to medium scale with screamer turned down. after a warm up period , adjust the screamer to wher is just starts getting to wail with the calibrated bottle. get the r11 vial at a supply house. that unit is pretty good
Getting an r11 vile at a supply house for the H-10G leak detector
Ok, so this vile thing, you're saying that the whole r11 vile is sold as a separate unit? I thought that you could refill it with r11. Anyway, if it's that easy, then I'll see if I can get one at a supply house.
Originally Posted by r404a
Someone said r22 will burn up the sensor in pure form. Well, the only thing I did was use a tiny amount of r22 gas to get the thing to go off, not in liquid form. So if you guys are telling me the facts, then surely I'll get the thing calibrated with r11.
I really love this unit. I am sure once it's calibrated, it'll not go off constantly like a fire engine. Very sensitive indeed, but like the forum guys said, the best unit out there.
This machine has endured the test of time. I bought my first one in 1966. Patience (as stated is the key). You will be fine with it once you get some practice. It is execellent for very small leaks in household refrigerators also.
If you really know how it works, you have an execellent chance of fixin' er up!
Tomorrow is promised to no one...
Used it for years, a very good unit. One point mentioned earlier, calabrate in an open air enviroment, let unit warm up first.
Note: I used to pick up on old cooler pannels, guessing the foam was expanded useing cfc's. Also would go off on truck exhaust , and propane floor buffers and fork lifts.
PATIENCE is the key.
The H-10 is by far the most sensitive refrigerant sniffer I have ever used. The key as I understand it is to adjust the calibration knob as you use it.
When I use mine (battery powered BTW), I turn it on and wait a few minutes. When it is warmed up, I adjust the knob until I get a tick-tick-tick around 1-2 per second. Then move the tip around where I want to find the leak. It will squeal when it smells gas. If it will not settle down, move the wand away and wait a few seconds. If it still will not settle down, move the wand away and after a few seconds re-calibrate with the knob. It just takes practice.
I am quite pleased with my H-10 with one exception: I do not do much HP work, so my unit does not get used much in heating season. I learned to bring it indoors and re-charge the battery once a month during the winter. The unit is VERY sensitive to battery voltage. It will 'act like' it is working, but will not tick/squeal... that means the battery is low or will not charge to a level of voltage the unit needs to work. Lucky for me, there is a wholesale sealed lead acid battery place close I can get a replacement. They run me about $35 give or take.
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