Audiogram An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer. The Y axis represents intensity measured in decibels and the X axis represents frequency measured in hertz. The threshold of hearing is plotted relative to a standardised curve that represents 'normal' hearing, in dB(HL).
Test every 12 hours not every 24 hours. The perfect time for sexual intercourse is within 12-24 hours prior to the ovulation predictor FIRST turning positive. Especially if you test only once a day. This may sound like a surprise, but making love only after first getting a positive OPK may not get you pregnant at all.
Do not rely exclusively on OPK results to time intercourse as you may not see an LH surge (positive OPK) even though you may be fertile. Your increased fertility begins before you see a positive OPK result since sperm can live in the reproductive tract for a few days in fertile cervical fluid.