|The display indicates Hi when the values are above those that can be indicated (eg greater than 1.999A).
is displayed when the absorbance value is less than zero.
The colorimeter should be calibrated to zero absorbance using a cuvette filled with the lowest absorbing substance to be measured, normally water.
If neg is displayed it is likely that the instrument needs to be recalibrated by inserting a cuvette with water (or the lowest absorbing solution) and pressing CAL.
is displayed when the batteries are low and need to be replaced.
This should be a very rare event.