Table 2.

Specification of instruments.

Instrument	Measurement	Measurement Range	Accuracy
Type-T thermocouple	Temperature distribution of container and packages, supply and return air temperature of refrigeration system	Element temp range is −195 °C to 371 °C, insulation rated to 105 °C	±0.5 °C [< 0.26%]
CO2 sensor, NDIR Non-Dispersive InfraRed, pass through type, 5VDC input	CO2 level inside of container	1 to 4.7 VDC for 0 to 30% Vol. CO2 Concentration linear	±[0.2%vol. CO2 ± 3% of measured value] ±[20 mV ±2% of measured volts]*8.11%/V
Figaro O2 sensor, Electrochemical Fuel Cell, pass through type, Amplified with 5 VDC input	O2 level inside of container	0.144 to Span Voltage (Calibration 20.8% Vol., value)	± 1%
Omega Differential Pressure Transmitter, Diaphragm Differential Pressure, 12 to 36 VDC input	pressure difference between inside and outside of refrigeration container unit	1 to 5 VDC for −10 to 10 IWG (Inch Water Gauge)	As good as calibrated 0.05%
Scale	weight	0–31.75 kg	0.567 kg