Temperature
Temperature was measured following DIN 12880 as much as physical limitations allowed. Validated PT100 temperature probes were placed in three locations in all 6 Cell Locker chambers in the System for a total of 18 locations tested. Each probe was located 1.5 cm inside from the front or back edge of the Cell Locker chamber, and equidistant from the left and right sides, such that they were in a straight line down the middle of the incubator, and the middle probe was in the geometric center. Each probe was positioned 1.5 cm above the culture tray, as shown in the Uniformity section. The humidity reservoir was filled to the maximum and the humidity was set to maximum. The incubator working under these conditions was left undisturbed for 12 hours before commencing the test measurement. Each measurement had a 10-second duration and the test continued for 22 hours.
Uniformity equals the difference between the highest and lowest recorded temperatures. Four different units were tested with 5 tests total.
Humidity
Humidity was measured using a FHAD 462 relative humidity (RH) sensor (AHLBORN, Germany) positioned in the geometric center of each Cell Locker chamber, with units equilibrating for 12 hours before testing. The humdity measurement table is a composite of multiple tests using 3 RH sensors in each of 3 Cell Locker chambers, and measurement was made following a 30-second door opening. Tests were performed 4 times on each of 3 different units for 12 tests total.
Carbon dioxide
CO2 was measured using a GMM221 infrared sensor (Vaisala, Finland) used without the protective cover and positioned in the geometric center of each Cell Locker chamber, with units equilibrating for 12 hours before testing. The CO2 measurement table is a composite of multiple tests using three CO2 sensors. Tests were performed 4 times (3 Cell Locker chambers each test) on 4 different units for a total of 16 tests.
Oxygen
O2 was measured using a FCX-MC95-C zirconium sensor (Pewatron, Switzerland) positioned in the geometric center of each Cell Locker chamber, with units equilibrating for 12 hours before testing. The O2 measurement table is a composite of multiple tests using three O2 sensors. Five different oxygen concentrations were tested in the same way (results not shown). Tests were performed on 2 different units.
Gas consumption
Gas use was measured using an electronic mass flow meter F-11B-10K-ABD (Bronkhorst, The Netherlands) positioned on the gas inlet port of the incubator. The gas consumption per day or per hour is calculated by measuring the gas flow (L/min) and multiplying by the amount of time that the gas valve is open. This total is then divided by the test duration time.
Evaporation rate
Evaporation of water was determined using 0.52 cm Petri dishes containing 15 g of distilled water, 3 dishes per Cell Locker chamber for a total of 18. The incubator was set to 37˚C, with the HEPA filter present and CO2 set to 0. After 24 hours 16 minutes, the dishes were weighed again using a precision balance 572 (Kern, Germany) with an accuracy of ±0.01 g. No incubator or Cell Locker chamber door was opened during the test period.