Triggering the HOBO Pendant G sometimes is a struggle. This is especially unuseful if you want to use it at a competition. You usually want to focus on anything else than getting a HOBO started. Learing the following this problem should be done.
Infrared blocks triggering
The HOBO Pendant G communicates by an infrared interface. As long as the logger gets any kind of infrared signal it is blocked to get triggered. In practice the HOBO can be triggered outdoors under cloudy conditions but not at sunny weather.
Reduce infrared radiation
To deblock you HOBO you need to reduce the income of IR-radiation (~sunlight) on the sensor (from both sides). Look for shade. Neither a waterproof marker nor tape seems to help here. I use a piece of bicycle tube.
Trigger it properly
Trigger the HOBO with a strong magnet at right edge marked red at the picture above. Wait until the red light blinked three times, the remove the magnet and wait another couple of seconds until the red light starts flashing fast. Ready to go.