Ice nucleating particle spectrometer

A spectrometer, comprising:

• a housing located on top of a chiller unit, the chiller unit comprising:
• a cavity configured to be filled with a coolant, and
• a coil positioned to be submerged in presence of the coolant;
• a hose to supply cold gas from the coil to a well area in the housing, the hose having a first end and the second end, wherein the first end is coupled to one end of the coil and the second end is coupled to a side of the housing;
• one or more metal blocks located inside the cavity of the chiller unit and positioned to be partially immersed in the coolant, wherein each metal block has a top surface with a plurality of indentations;
• a thermistor located in one of the one or more metal blocks to measure temperature of a region surrounding the one or more metal blocks;
• one or more sample trays located on top of the one or more metal blocks, wherein each sample tray comprises a plurality of wells that extend downwards from a bottom of each sample tray and that fit within the plurality of indentations of the one or more metal blocks;
• a lid to cover the plurality of wells to insulate air above the plurality of wells from room temperature air;
• a camera located on a top surface of the housing to capture images of samples located in the plurality of wells;
• a plurality of light sources located on the housing to provide a stable lighting environment in the housing;
• and
• a computing device comprising a processor and a memory including instructions stored thereon, wherein the instructions upon execution by the processor configure the computing device to:
• program the chiller unit to reach a certain end temperature to freeze samples located in the plurality of wells;
• and
• record, using the camera, an intensity of light reflected from the samples located in the plurality of wells at least during the temperature of the chiller unit is adjusted.