I purchased a TekPower TP4000ZC multimeter, which has no backlight for the LCD.
I wish to add one myself, perhaps a single led at low current, driven directly off of the two AA batteries. I'll add a small toggle switch as well for saving the battery.
I'm wondering if there's any reason not to do so.
Could this end up altering a reading?
I know the multimeter has to accommodate a battery that diminishes in power anyway, so I'm assuming the small drop won't be an issue. However I'm worried there may be something I'm not considering, as multimeters measure several parameters with high sensitivity and have many components in close proximity. I could see some sort of tiny EMF or other phenomenon occurring right next to a component and changing a reading, making this a waste of time.