Secador Automatic Desiccator vs. Comparable Competitor March 2011 Bel-Art Products Engineering Department Wayne, NJ Page 1 of 6
Table of Contents Table of Contents... 2 Objective... 3 Test Conditions and Protocol... 3 Data Points to Collect... 3 Models to be Tested... 3 Summary of Conclusions:... 4 Test Results and Discussion:... 4 I.Start-Up and Time to Reach Steady-State:... 4 II.Steady-State with Doors in Closed Position:... 5 III.Doors Opened 1x per Hour over Nine Hours Test Duration:... 6 Page 2 of 6
Objective To test the performance of the Secador automatic desiccator against a desiccator of comparable size and type, and under identical test conditions. Test Conditions and Protocol Test data presented and discussed in this report were gathered under the following conditions: The desiccators to be compared were placed in a controlled environment chamber where the relative humidity (%RH) level was maintained at 73% RH by means of a saturated salt solution. Temperature in the chamber was maintained at 75 F. No bottles or other materials were placed inside either desiccator. Once activated, the desiccators operated continuously for 96 hours without entry. After 96 hours, the Frequent Door Opening test was initiated. After this 9 hour protocol each desiccator was operated for an additional 63 hours. 1.) Initial Start-up and Time to Achieve Steady State 2.) Steady-State Conditions with Closed Door 3.) Frequent Door Opening - Once initiated, each desiccator door was held open for 30 seconds, at a 90 angle to the unit, once per hour, for a period of nine (9) hours Data Points to Collect Temperature and humidity were logged at 1 minute intervals inside each desiccator and in the environmental chamber space outside the desiccators. Power consumption was also measured for the automatic Secador vs. the competitive model. Power consumption data is not shown in this report because there was no relative difference between the models. Models to be Tested The following Automatic models were tested according to Test Conditions # 1, 2, and 3. 420741115, Scienceware Automatic Secador 4.0, Vertical Profile Desiccator, 120V Desiccant Regeneration Interval: 20 minutes (72 times per 24 hour period) Interior Volume: 1.9 cu. ft. Suggested List Price: $1007.75 vs. Competitive Model X, Vertical Profile Desiccator, 120V Desiccant Regeneration Interval: 5 hours (4-5 times per 24 hour period) Interior Volume: 2.1 cu. ft. Suggested List Price: $1475.10 Page 3 of 6
Summary of Conclusions: Overall the automatic Secador desiccator outperformed the comparable competitive model. Consistency in maintaining a low %RH was superior in the Secador desiccator and became more apparent during testing designed to model frequent entry to the desiccator interior. In addition, steady-state was achieved more rapidly by the Secador desiccator at initial start-up, as well as during the recovery period after entry. Competitor X at its best had a slightly lower (13% vs. 17%) relative humidity. While these relative humidity levels are both considered excellent by industry standards, the lower variability and faster response times for the Secador desiccator demonstrates its superiority over Competitor X. Given the comparable interior size of each desiccator and quality of materials, construction and functionality, it is concluded that the superior performance of the Secador desiccator is attributable to its more frequent and more efficient Desiccant Regeneration Interval of 20 minutes vs. 5 hours in Competitor X. Test Results and Discussion: I. Start-Up and Time to Reach Steady-State: Discussion: On initial start-up relative humidity in the Secador desiccator drops from 73% (consistent with environment chamber) to 20% in just 7.5 hours. In contrast, Competitor X takes 5 times as long (38 hours) to reach the equivalent relative humidity of 20%. Steady-state levels of 17% (+/- 2%) are achieved in the Secador desiccator in approximately 9 hours, whereas Competitor X is at still at 42% RH and requires almost three days (68 hours) to achieve a steady-state level. While Competitor X tends to reach a lower relative humidity (%RH) level at steady-state (13% vs. 17%), the Secador desiccator maintains much tighter control of relative humidity, as evidenced by less variability in the %RH levels. Conclusion: Secador outperforms Competitor X on initial start-up. Page 4 of 6
II. Steady-State with Doors in Closed Position: Discussion: At steady-state the Secador desiccator maintains much tighter control of relative humidity as evidenced by less variability in the %RH levels (15% to 19% RH for Secador desiccator vs. 10% to 23% RH for Competitor X ), and with the majority of time at the still narrower RH range of 16-18%. Competitor X, which has a longer desiccation regeneration interval (5 hours vs. 20 minutes), at its best provides lower relative humidity (%RH) levels, but within each cycle relative humidity levels can rise to as high as 22%. Conclusion: The Secador desiccator outperforms Competitor X in maintaining more consistent and low relative humidity levels. Page 5 of 6
III. Doors Opened 1x per Hour over Nine Hours Test Duration: Discussion: During the course of the nine hour door opening test, the Secador desiccator has a relatively minor rise and variation in %RH levels, never going above 30%RH. In addition, once the door opening test ceases, Secador returns to its normal steady-state more rapidly than Competitor X and the range of variation in RH levels narrows very quickly (A). In contrast, variation in %RH for Competitor X is much larger and overall %RH increases significantly over the nine hour test period. Also, Competitor X takes approximately 3.5 hours longer to reach %RH levels consistent with the Secador desiccator steady-state (B). These differences in %RH variation and time to steady-state can be attributed to differences in the regeneration interval for the desiccators. The Secador regeneration interval is only 20 minutes, whereas Competitor X requires 5 hours to complete a cycle. Note also the large spike in Competitor X %RH levels at the 14 to 15 hour time point (C). One theory for this observation is that over the course of the nine (9) hour test period, the Competitor X desiccant was so highly saturated that once the next regeneration cycle began, the high quantity of water vapor being driven from the desiccant entered the desiccator chamber rather than venting to chamber exterior as it should. Conclusion: Under conditions simulating heavy-use as demonstrated by frequency of door openings, the Secador desiccator outperforms Competitor X by maintaining a narrower range of relative humidity, an overall lower level of relative humidity, and by returning to steady-state in a shorter time frame. Page 6 of 6