The cell cable for the WaveNow family potentiostats provides an analog ground line (black lead). However, sometimes it is necessary to ground the working (red lead) or counter (green lead) electrode. How can this be done?
The WaveNow family potentiostats are not connected to Earth-ground through the AC mains power supply adapter. However, a path to Earth-ground *MAY* exist through the USB cable. The analog ground (black cell cable lead) is by default internally electrically connected to the USB ground line. That means that the counter, working, and reference electrodes MUST NOT be connected to Earth-ground, either directly or through other Earth-grounded equipment.
A provision has been made to isolate the USB connector (and its ground) from the other electronics in the potentiostat, thereby created a “floating” instrument, and as such ONE of either the working (red cell cable lead) OR the counter (green lead) can then be electrically connected to a common Earth-ground. Grounding the working electrode has been observed to produce more environmental electrical noise in the data than grounding the counter electrode does.
WaveNow family potentiostats manufactured after the 23rd week of 2012 include a jumper to control this grounding option. On earlier units, there is a zero-Ohm resistor which must be removed from, or added to, the circuit board (note that since it is zero Ohms a simple “solder bridge/blob” or wire can be laid across the pads to complete the circuit, an actual resistor is not necessary). The default configuration for all versions from the factory is for all grounds (digital, analog, and Earth) to be connected in common – meaning the working and counter electrodes SHOULD NOT be grounded unless the modifications shown below are made.
The manufacture date can be determined from the first 4 digits of the 7-digit serial number on the white bar-coded label on the bottom panel. The format is week+year+number as wwyynnn (e.g. units manufactured in the 23rd week of 2012 will have serial number 2312nnn). See photos below to identify and locate the grounding options.