ALPA_CALIPER_IP66
REL BUTTON - For switch-on power, switch-off power, zero-clearing and presetting
Press REL button shortly to switch on power when power is off. It'll clear zero by pressing ZERO key
shortly at non-setting mode. Meanwhile, turn measuring mode to incremental mode. It will increase
current digit whose bit has been changed by for example pressing shortly ZERO key in setting mode.
If it's over maximum value for this bit, just put digit back to 0. Press REL button for long to switch off
power after measurement is over.