The purpose of the article is to understand why the low battery light indicator comes on.
Three sets of new Duracell batteries were tested, in several Fluke-1587 FC's and Fluke-1587's, with the same result. When switching directly from OFF to INSULATION function, the low batt indicator will come on.
By performing a high current battery test (press hold button while turning the meter from OFF to the INSULATION mode) the symptom can be made to disappear. In other words, the meter will no longer display the low battery warning, when switched from OFF to INSULATION mode, subsequent to having performed the battery load test.
The above has been attributed to internal battery impedance that is added to the Duracell batteries, by design, during their manufacturing process. The added impedance is to protect the battery from leakage during storage. The added internal impedance is supposed to reduce when a load is applied to the battery.