Monitor and troubleshoot HVAC systems, verify energy management systems, or track performance of pneumatically controlled valves with Series DL6 Pressure/Temperature/RH Data Logger. Units include an on-board thermistor for ambient temperature measurement and pressure module. Remote humidity/temperature sensor and plug-in humidity sensor are sold separately. Loggers can store up to 32,768 readings and operate independently from any external power supply with built-in lithium battery. Use Model DL200 Windows® software (sold separately) to quickly program the logger or upload data to the computer.