Electrometer is hard to zero or shows values that change rapidly

Precautions for use of and changing batteries within an electrometer.

The electrometer is an exceptionally sensitive device.  When you are zeroing the electrometer, please make sure to have the two leads connected to each other so that any residual charge that may be on the leads can flow so that there is not potential between the leads.  Please make sure that, when the electrodes are connected to each other that you stand as far away from the device as possible when you are zeroing it.  Synthetic clothing or wool can also be an issue as these fabrics can develop and hold charges that can be picked up by the electrometer.  Charged clothing can radiate electric fields out several feet.  If you have access to an electrostatic mat, this can also be helpful in shielding the electrometer leads from residual charges that may be present in plastic counter tops that can lead to measured voltages (especially on the highest sensitivity settings for the electrometers).  When using this device, please make sure to use it outside of any drafts that can be caused by the air conditioning system.  Air movements can cause to charges developing on the leads and cause the electrometer to not be able to zero. 

When changing the battery within this device, it is critical to not touch the circuit boards.  Please use rubber gloves when changing the battery to make sure that no skin oils are deposited that could lead to charge leakage.