budleydoright
Well-Known Member
PPM4 is kind of a piece of crap. It uses a semicinductor sniffer which is about a 2.00 part. All of the others use NDIR infra red sensors whch is the current state of the art in detection. Plus you never know what your actual numbers are. You could be overshoothing to 3000ppm and never know it.
Go on ebay, there are always PPM3s, PPM3 knock offs or telaire based units, digigros etc for just a little more than the ppm4. I have a digigro and popped the relay in it. they sent me an upgraded version at no charge that has the external relay.
Go on ebay, there are always PPM3s, PPM3 knock offs or telaire based units, digigros etc for just a little more than the ppm4. I have a digigro and popped the relay in it. they sent me an upgraded version at no charge that has the external relay.