This article presents the customization of EJS models, used together with actual laboratory instruments, to create an active experiential learning of measurements. The laboratory instruments are the vernier caliper and the micrometer. Three computer model design ideas that complement real equipment are discussed in this article. They are 1) the simple view and associated learning to pen and paper question and the real world, 2) hints, answers, different options of scales and inclusion of zero error and 3) assessment for learning feedback. The initial positive feedback from Singaporean students and educators points to the possibility of these tools being successfully shared and implemented in learning communities, and validated. Educators are encouraged to change the source codes of these computer models to suit their own purposes, licensed creative commons attribution for the benefit of all humankind.