Models 8511 and 8512 from Calex Mfg. Co. Inc., Concord, CA, are single-point, isolated thermocouple to frequency signal conditioning modules. The 8511 works with a Type J thermocouple over a 0°C–500°C temperature range while the 8512 works with a Type K thermocouple over a 0°C–500°C range. Both include linearization and cold-junction compensation and provide a 100 Hz output frequency at 0°C and 5100 Hz at 500°C, with 12-bit resolution. The output optocoupler provides DC isolation from the input and the 24 VDC power. The module outputs work with 24 V, 7 mA PLC high-speed counter inputs. Applications include remote temperature monitoring.