I don't have a pic of a moisture meter, handy...but, they are sold at Lowe's, Home Depot and any good home & garden center. About $3-$6.
They have a 8 inch metal probe that you stick into the soil pot. By going much deeper than your finger can...it's reads: WET-MOIST-DRY.

Some of the newer models even have a light meter setting and a PH setting!...how acturate?..I don't know...but it's better than nothing....I suppose. The moisture setting is very, very accurate.