Di-Log-Proving-Unit-For-Voltage-Testers-c-w-Continuity-Test-PU260-Di-Log-PU260-P-It-is-a-recommendation-of-the-HSE-given-in-guidance-note-GS38-that-voltage-indicators-nbsp-should-be-proved-before-use-&-after-use-BR-Test-Lamps-&-some-voltage-indicators-may-fail-to-danger-e-g-a-faulty-lamp-not-indicating-a-live-circuit-These-devices-should-be-proved-before-&-after-use-on-a-known-live-source-or-similar-voltage-to-the-source-under-test-or-alternatively-on-a-portable-test-