Would you please provide me with a step by step method of using the bounty Hunter Land Star which I bought to detect brass water valves in sand approx 5 to 19 inches deep. The valves, looking from the top, are 2 1/4 inches long, and 1 1/2 inches wide. The valves have a 2 1/2 inch diameter handle to turn the valve made of pot metal. This handle is perorated. I am a volunteer water department person that needs to be able to locate these valves to turn resident's water off at the street. So far I have not had any luck. Thank you.