standard lead (lēd)
Any of three standard bipolar limb leads of an electrocardiograph, designated I, II and III. Lead I records potential difference between the right and left arms; lead II, the difference between right arm and left leg; lead III, the difference between left arm and left leg.
A record obtained from such a lead.
In standardising the chromate solution, the standard lead nitrate solution is used.
The standard lead solution is then run in till the tints are equal.