I got a new chronograph last winter and have used it about 5 times. I believe it's a comp electronics model. The first time I used it I had to move it around several times to get a reading. The next 3 times I used it it worked every time. Tonight I fired seven rounds with none of them registering. I moved it up and down, made sure it was centered and it was placed about 5 feet past the muzzle. It was a bright clear day, but it was early evening with a couple hours of light left. I tried turning it on and off, taking out the battery. How sensative are they to light conditions and positioning? Any other things to check?