A refrigerant monitor from Grainger measures superheat or subcool refrigerant with direct connections for temperature and pressure. Some models also measure humidity, air flow, and psychrometrics. Shop here for a multifunction expandable meter, a superheat/subcool meter and a multifunction instrument kit with five different probes and a hard carrying case. For expert refrigerant measuring and monitoring, and to help ensure your heating and cooling system is operating efficiently, get a refrigerant monitor from Grainger.