【名词&注释】
环境温度(ambient temperature)、制冷剂(refrigerant)、电磁阀(electromagnetic valve)、临界温度(critical temperature)、差压变送器(differential pressure transmitter)、凝固点(freezing point)
[单选题]调火电磁阀的输入信号来至于()。
A. (A)差压变送器(differential pressure transmitter)、手动调水
B. (B)差压变送器(differential pressure transmitter)、气源
C. (C)手动调水、差压变送器(differential pressure transmitter)
D. (D)手动调火、差压变送器(differential pressure transmitter)