Even the cheapest digital voltmeters have 1MOhm input impedance<p>The one the parent mentioned has 10kOhm&#x2F;Volt sensitivity, so for 10V range it gives 100kOhms<p><a href="http:&#x2F;&#x2F;support.radioshack.com&#x2F;support_meters&#x2F;doc73&#x2F;73794.pdf" rel="nofollow">http:&#x2F;&#x2F;support.radioshack.com&#x2F;support_meters&#x2F;doc73&#x2F;73794.pdf</a>