DTS-BE ultra-portable intelligent constant temperature oil bath is a high-precision automatic control temperature verification device, which has the characteristics of good temperature stability, uniform temperature field and high temperature control accuracy. Adopt fully enclosed compressor refrigeration system and intelligent PID adjustment to realize automatic temperature control. The bath is compact in structure, light in weight, easy to carry and durable. It is suitable for the on-site verification/ calibration of various types of industrial thermal resistance, low temperature thermocouples, armored thermocouples, working glass liquid thermometers, standard mercury thermometers, bimetal thermometers, pressure thermometers and other temperature sensors.