Keep a eye on the power from your machine with this mA-meter.
Recommended max power is 18mA for the 40w tubes to prevent early aging or overpowering the tube.
All meters we sell is calibrated and checked to confirm correct readings. Many meters from china do measure up to 20% wrong, all our meters has a maximum error reading of 3%
(we get the bad ones too, we throw them away and only sell the good ones)