mpo55Danfoss MP 55 Differential Pressure switches delay of relay 90 sec. 060B017291 Adjustment Cut out for falling pressure. Ambient temperature -40 - 60 °C. Ambient temperature -40 - 140 °F. Ammonia application No. Approval CCC, CE,The MP55 is the ideal starter model and offers simultaneous determination of up to 3 melting pointmelting range or 2 slip melting point samples up to a maximum temperature of