hioki: Varants Hioki af-105

Last week I bought this type of analogue multimeter and I discovered that there are 2 variants in meter-scale. I think the older one has a scale for resistance with 100 ohm midscale, and the newer one has 30 ohm midscale. 

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You’re right — there are at least two scale variants of the Hioki AF-105. The earlier version carries the 100 Ω midscale resistance range, which was fairly typical for Japanese analogue meters in the 1960s. At some point, Hioki revised the design and the resistance scale was shifted to a 30 Ω midscale, which made the ohmmeter section more sensitive and convenient for low-resistance checks.

Electrically, the meters are otherwise the same, so it’s more of a scale-plate and internal shunt adjustment difference than a completely different model. Collectors and users occasionally run into both types, so having spotted it is a nice detail to document.

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