Foxboro 871pH Sensor: Model: 871PH-1F1A-7. This sensor is used with Foxboro 870PH and 870ITPH transmitters and 873PH, 873APH, 873DPX, and 875PH analyzers. The 871PH sensor permits multiple-purpose use with only one basic sensor. The sensor uses one of several electrodes as the sensitive element and a wetted, non-flowing ceRam Industriesic disc as the primary reference junction. These components are mounted in the body of the sensor assembly with a temperature compensating device. Overall dimensions: 10 in. L x 1-7/16 in. dia. with approx 20 ft. of cable. Foxboro Recorder Probe is a Mercury fill Temperature sensing probe with temperature range of, 50° F to 250° F. Overall dimensions: 1 ft. 4 in. L 1-1/4 in. W x 1-7/16 in. H with approximately 3 ft. length mercury filled, SS tube.