Pieps Micro Avalanche Beacon
By Shaun King, ACMG Mountain Guide

2019

Background
In the quest for lightweight, compact ice climbing avy gear, I was naturally drawn to the new Pieps Micro. Compared to my already light and svelte BCA Tracker 3, the Micro was 50g less (including batteries), about 1 cm shorter, and a bit narrower in profile. Add to that a revolutionary sensor technology, auto antenna switch, and many other novelty features and my curiosity was piqued.

Functionality
One of the things that has always bugged me about transceivers is the send/receive switch. You want something that is easy to do one handed without taking your gloves off (unlike most units currently on the market). You also want a switch that is easy to put back into send mode (in the event of a secondary slide while searching) but won't be switched over by accident, like the BCA Tracker 2. It seems an impossible ask of a switch; but what if there was no switch? Well there isn't on the Pieps Micro. Pull the unit out of its harness or your pocket and a sensor tells it to go into search mode. "Say what?!? OK but then you put it back into your pocket for probing and it reverts right?" Nope. It is now locked on search even when the sensor is covered. "OK but then you get buried and you're screwed right?" Nope. After one minute of being motionless it assumes you are buried and reverts to send. "Are you kidding me? This thing is smart!"
When you first turn it on, the unit does an extensive self check before counting down from three and going into search mode. If you want to perform a group check function, just push and hold the flag button (the only button) before the countdown ends (it's much faster than the check function on my Mammut Pulse). Once you put the beacon into the harness or a pocket, it vibrates ten times to let you know it is sending (along with the standard flashing LED indicator).
There are three different group check function modes; regular, extended (for older analogue beacons), and pro (which can alternate between send and receive by tilting the unit). You can enable or disable the various modes via the Pieps mobile app.
The revert to send function is another feature that has annoyed me on other beacons. Having this feature as automatic after a certain time period seems ridiculous to me and is sure to confuse rescuers in the heat of the moment. I usually tell novices to disable this feature if they can. The thing I like about the Micro is that the auto revert only happens after 60 seconds of complete motionlessness. The unit will give auditory and vibrational warnings before auto reverting (in case it was left on a pack for example) and will continue to whine while in send mode (like an emergency service vehicle) until the flag button is depressed and held. The time lag for auto revert can be changed to 90 or 120 seconds, but it cannot be disabled.
Another impressive feature with this transceiver is the intelligent transmitter, which detects when the transmitting antenna may be compromised by electrical interference (i.e. from a mobile phone) and switches to another antenna for transmitting the maximum range to searching beacons.
Somehow Pieps was able to get away with a single AA battery to power this beacon, which plays a significant role in decreasing the weight. They advertise that an alkaline battery will last 200 hours, and a lithium is good for 350!
One cool thing about modern beacons in general is that the internal software is upgradeable. With my Mammut Pulse I had to (sometimes pay to) have a dealer perform the upgrade. With my BCA Tracker 3 I could do the upgrades at home, but I had to download the software and plug the unit into my computer. With the Pieps Micro I simply downloaded a free app to my phone in order to Bluetooth the updates and change other settings like group check functions, auto revert times, battery types and get a full diagnostic. Pretty sweet.

Performance
My initial plan was to use this beacon mainly for ice climbing, but with the light weight and compact design I ended up using it almost exclusively over the winter. While teaching avalanche courses I was able to compare its performance to other beacons being used by the students.
For single beacon searches it was fast and easy. During the signal search, the unit vibrates upon initial detection of a signal, allowing you to focus on visual clues during the early search. Five display arrows and large numbers with an illuminated background made it very easy to read in all lighting conditions. The processor provided readings in real time and allowed me to move quickly with the inputs. In fine search the arrows disappeared at a range of two metres and bracketing was straightforward.
Individual stickman icons on the screen indicate whether the unit is detecting one, two or three signals. An additional icon indicates when detecting four or more signals. Within a 5 m radius you can mark a signal which puts a box around one of the stickmen to indicate that it has been marked. In multiple search mode the mark function allowed me to reliably find all the beacons without having marks get dropped; however, the buried beacons were usually all the same (BCA Tracker 2s). The Micro was easily able to switch between buried units without much signal lock which made strip searches easier.
The group check function worked predictably. You just need to keep the mark function button depressed or press it again before the three second time-out. I found the button required enough pressure to make my thumb sore if waiting for a large group to cycle through. I personally didn't bother with the "pro-mode" which seems like a neat feature, but you would have to keep your thumb on the mark button for even longer then.

Carrying
The Micro comes with a well engineered harness that allows the beacon to snap in and out of a plastic holder which requires enough force to prevent accidental discharge (in the event of an avalanche) but seems easy to do with gloves on and requires no manipulation of finicky buckles. A built in elastic leash can be girth hitched to the unit, so it stays attached to the harness but can easily be held at arms length for searching. There is no plastic attachment clip to break.
Also supplied with the unit is a hand leash and a microfiber bag for storage in a "securely closeable clothing pocket". Personally, I hate wearing a chest harness, so I went for the pocket option. The leash had no clip to attach to a belt loop and would not stretch to allow extension from an attachment point anyway, so I replaced it with the bungy leash from my BCA Tracker 3. I personally had no need for the microfiber bag, but it may be useful to engage the proximity sensor as I have read that this may be an issue when wearing baggy pants. I was not able to recreate the problem in simple tests with baggy pants pockets myself; even while holding the pocket as open as it would go and slowly sliding the beacon in, I was not able to trick it into staying in search mode.
One issue I did experience on three occasions over the course of the winter was having the transceiver switch itself over to receive mode while in my pocket for no apparent reason. I realize that this does not constitute a safety concern because of the revert to transmit if I were buried, but it is disconcerting nonetheless. The Black Diamond rep said he had not heard of this issue with other beacons and would have the engineers start an investigation, but it is good to hear that my unit seemed anomalous.

Advertised Stats
Searching Antennas: 3
Maximum range: 50 m
Search strip width: 50 m
Weight with batteries: 150 g
Dimensions (LxWxH) 106 x 74 x 20 mm
Battery lifetime: 200 min. (Alkaline); 350 min. (Lithium)
Temp. range: -20C to +45C
Additional Functions: Self Check, Auto-Antenna-Switch, Auto-Search-to-Send, iProbe Support, Sensor Technology, Vibration, Bluetooth updates
Pros:

• Light and compact; only needs one battery
• Slick, hands free switch to search mode
• Always transmits on strongest antenna orientation
• Bluetooth updates are a snap

Cons:

• Battery display in thirds, not percentage
• I experienced an auto revert issue

Conclusion
Generally, I was very impressed with this beacon. Mainly because of the size and weight, but I loved the simplicity of all the "smart" functions and the Bluetooth capabilities. It seemed basic enough for a novice but functional enough for a pro. I have always marvelled at how much technology goes into a smart phone and how primitive radios and transceivers are in comparison. I think the Pieps Micro has paved the way for the future of beacon technology.