The term 'HEAT MEAS' is an abbreviation for heat measurement, and can be represented by four different acronyms: KCAL (4 letters), BTU (3 letters), CAL (3 letters), and BTUS (4 letters). KCAL stands for kilocalorie, which is a unit of energy equal to 1000 calories. BTU stands for British Thermal Unit, which is a unit of energy used in the power, steam generation, and heating industries. CAL stands for calorie, which is a unit of energy equal to 4.184 joules. Finally, BTUS stands for British Thermal Units per Second, which is a unit of power equal to the energy transferred per unit time.