Impedance Check and Calibration

Before using the BrainMaster module to collect EEG data, we need to check the impedance level and to calibrate the module first, right ? My questions are:
1) How can I check the impedance ?
2) How can I calibrate ?
3) Do I need to go through these two steps every day (we’re collecting 4 subjects’ data every day) ?

We have impendence checkers available:
Checktrode $350.00. You may want to
invest in one for your neurofeedback needs.

There is no calibration or adjustment to the BMr module,
excepting the possibility that it needs to be repaired.

I wonder if you are seeing the signal due to motion
or other picked-up artifact. Do you braid the lead
wires together? It is a good idea to braid them together,
to remove many sources of artifact signal.

Please try braiding the lead wires, and making sure
that they are not being moved or touched during
the recording. This should give you a clean signal.
Do the test with the electrodes toucing together,
to look for the flat line.