New Garmin MK2i T1 problem

[Open Ocean Diver]

Just bought a new MK2i and was planning on diving Friday to get it wet for the first time. Having an issue with air integration data from the transmitter, in single gas setup the reading is low compared to two SPG’s and an Atomic computer. With a tank at 1830 psi, the descent reads 132 psi lower, at lower tank pressures the difference increases approaching 178 psi tank at 520 Psi. Garmin suggested removing the transmitter battery to reset the unit, deleted the sensor and repaired a couple of times, updated the software. Nothing has helped.

Was wondering if any other users are having the same problem?

Any suggestions would be appreciated.

Thanks,

 

[tbone1004]

I wouldn't worry about it vs the analog SPG's unless they agree with the Atomic. Make sure the batteries are full as that can affect sensor readings.

 

[Open Ocean Diver]

I wouldn't worry about it vs the analog SPG's unless they agree with the Atomic. Make sure the batteries are full as that can affect sensor readings.

For the heck of it I replaced with a new battery. Both analog gauges and Atomic read the same. Thanks

 

[scubaozy]

I think they are poorly calibrated. I have two (first one was lemon and replaced) and both show up to 25bar less than actual. I am also looking for a way to recalibrate them.

 

[Open Ocean Diver]

Seems to be way out of spec especially at the low end at 650 psi off by 27%. Waiting to hear what Garmin has to say. Not sure if I should replace the sensor or the watch too. If it wasn’t new I’d take the sensor apart although I’m sure calibration is done using special software. No more analog pots. Frustrating not to have it work right out of the box.

Garmin Descent MK2i

Atomic - MK2i

1860 - 1726 = 134

1850 - 1703 = 146

1690 - 1535 = 155

1350 - 1185 = 165

980 - 803 = 177

790 - 612 = 178

650 - 474 = 176

520 - 342 = 178

370 - 192 = 178

330 - 192 = 187

230 - ——- no comms

 

[scubaozy]

Yours is deviating roughly 10-12 bars, I am at 25 bar deviation. I am past disappointment, the first unit only worked the first day of a 12 day liveaboard. Second one is way more inaccurate than first. I already lost the interest in it, I don't even care anymore. There is nothing much inside the unit, if you undo the screws, it will just pop, secured by 2 o-rings. Most of the device is battery bay. If you are unhappy return it imho. I was suspecting the air restrictor might be the problem if it is not the calibration problem. I would expect this type of device to auto calibrate at every time before shutdown where it is expected to be 0 but what do I know?

 

[scrane]

That kind of accuracy, especially at the low end of the scale, is TOTALLY unacceptable. Dangerous and potentially fatal.

Readings are battery level dependent? Gosh.

 

[Open Ocean Diver]

Returned to the dive shop, they verified the issue and replaced the transmitter for me, very helpful. Garmin tech support was excellent also.

 

[Open Ocean Diver]

Shop compared my transmitter with their shop transmitter to their digital gauge used for fills. Mine was about 100 psi off and their transmitter annoying to them was over 170 out compared to the digital… tank 1500 psi. So now I understand a little more clearly why we surface with 500 psi. Gauges may be out by 250. Unbelievable. My two SPG and Atomic digital read the same but apparently none of them are accurate. Amazing you can find a digital pressure gauge from 0 to 10,000 psi, .25% accuracy for less than $100. My gas gauge is more accurate than my pressure gauges. SPG‘s should be more like gas gauges what’s the point having any numbers, full, 3/4, 1/2, 1/4 and empty.

 

[stiebs]

Amazing you can find a digital pressure gauge from 0 to 10,000 psi, .25% accuracy for less than $100. My gas gauge is more accurate than my pressure gauges

Who's to say the digital gauge is the more accurate of all the ones you checked? Just because it's digital didn't mean it's accurate.

A digital gauge, no matter what it is measuring (pressure, weight, flow, gas) is always a sensor that outputs an analog signal (a variable voltage, resistance or current, or a physical mechanism that in turn generates a variable voltage, resistance or current) which is then converted into a digital signal.

In the case of a transmitter, that digital signal is converted into a radio or sonar signal. In the case of a digital shop gauge, the signal is converted to a numeric value and displayed on the LCD.

The accuracy comes to quality of design and engineering, calibration and tolerances - for both digital and analog.

Much like for your car, with diving the expense of engineering, building and calibrating an SPG or transmitter to be highly accurate outweighs the benefit.

As you said, it doesn't really matter what your turn pressure is. It matters what percentage it is from where you started.