This happens in pharmaceutical companies which use Wet and Dry bulb Hygrometers

This blog details our attempts at developing and marketing an automated Temperature and Humidity monitoring system to a Pharmaceutical company that largely depended on using Wet and Dry bulb Hygrometers to log the Temperature and Humidity.


If you don't know why a Pharmaceutical company may need temperature and humidity monitoring click here to find out why. If you are in a hurry, please skip forward to the "Observation and Analysis" section.

What we were trying to do:

Inventrom PVT LTD is an IoT start-up specialising in making end products that drive massive benefits, but at the same time are very easy to use. After our phenomenal success with the Bolt IoT platform, we decided that it was the right time, to venture into developing an IoT-enabled product that would be very easy to use, would make the lives of our customers easier, and most importantly would solve a customer problem.


We spent months deciding what to develop, and then a few months more developing and perfecting an automated temperature and humidity monitoring and alerting solution. We named this solution Blake, and We had been confident that Pharmaceutical companies would readily accept our solution, as we truly believed that it was a better alternative to using a wet and dry bulb hygrometer.


Blake is an automated temperature and humidity monitoring and alerting solution, that not only logs  the temperature and humidity data in your labs but also sends you SMS and email alerts when the temperature or humidity in the labs moves beyond acceptable limits.

The problem that we faced.

With a perfected product in hand, we approached a few pharmaceutical companies, and quite a few of them readily accepted the solution, until we met a company (Let us call this company, company X to protect their identity) which was on the border of accepting our solution but was not sure about the accuracy of our system. Since Blake uses the HYT939 sensor, it can run circles around any Wet and Dry bulb Hygrometer when it comes to accuracy. So we decided to hold an experiment at company X's labs to convince them of  Blake's accuracy levels.


The experiment would be simple, a Blake unit would be placed in their lab next to the Wet and Dry bulb hygrometer and would log the Temperature and Humidity data, while the standard procedure for logging data from the Wet and Dry bulb hygrometer would be followed. We had asked Company X for their SOP for logging the Hygrometer data and found it to be acceptable. The experiment would last a week, and we would compare the data from the two sources at the end of the week.


The results of the experiment shocked us. There were unacceptable differences between the reading logged by the workers at Company X, and the reading logged by Blake. Furthermore, the differences in the reading were neither constant nor did they have specific limits as we had expected,  as a result, we concluded that we could not even calibrate the Blake to the Hygrometer to get more favorable and consistent results.


If your lab uses Wet and Dry bulb Hygrometers to monitor the environment, please read further only at the risk of completely losing trust in the Wet and Dry bulb hygrometer.

Observations and analysis

We were thrown completely off-guard by the mixed results, and we thought maybe some condition in the lab was causing the Blake to malfunction. So to investigate we sent one of our engineers  to monitor the device for a 2nd round of the experiment. While the engineer found no Malfunctions in the Blake, the infractions he noted regarding how the Wet and Dry bulb hygrometer was read and logged shocked us all. Here are the issues that the engineer noticed.

1. The SOP required employees to log the Temperature and Humidity data at specific time intervals. More often than not, the employees would be late in logging the data. But while logging the data, the employee entered the time within the interval into the logging sheet. For example, a reading taken at 5 pm, was logged to have been taken at 4 pm.

2. To measure the Humidity, using a wet and dry bulb hygrometer, it is required for an employee to look up the Humidity data via a lookup table. Several employees had memorized the tables and used to log the data correctly without looking at the tables. While some others who had not memorized, who had seen the earlier employees, had fallen into the pretense that you only had to write acceptable humidity limits. It didn't matter to them what the actual value was.

3. The issue had gradually traveled through the employees, and some employees would log acceptable values of temperature with the same miss-guided concepts.

4. The Wet and Dry bulb Hygrometer suffers from water vaporization issues at low humidity levels. This causes the cotton tube to dry up. Once the cotton tube would dry up, the Wet and Dry bulb Hygrometer would yield a wrong value for Humidity.

5. The SOP contained steps to check whether the cotton was dry, and if it was dry, it had to be made wet, and the employee would have to wait 15 minutes before logging the new data. In a hurry, the employees would log acceptable limits of temperature and humidity to get to their next task quickly.

6. At one point in time, the Hygrometer and the Blake yielded the same Temperature and Humidity values. Our technician was elated, and took a photo of the Hygrometer as proof, as the employee responsible for logging the data was late. When the responsible employee arrived, he was shown the photo as proof of the value. Despite the proof, the employee did not log the data from the photo. This was because these values were outside the acceptable limits, and he did not want to get in trouble with his boss.

Conclusions and Resolutions.

Through this experience, we learned that it would not be possible for us to show company X, that Blake would provide accurate data. As such, we reported all of the incidents that we noted earlier to executives at company X.


To protect the identity of company X, we cannot reveal to you whether they decided to stick to wet and dry bulb hygrometers or to start using the Blake temperature and humidity monitoring system. But we are certain, that the executives lost sleep during the time that they were deciding whether to use Blake or not.


Now here is a question to you, would you want to lead a company that replaces wet and dry bulb hygrometers with automated logging solutions or would you want to lose sleep over when your logging system would fail?


To know more about Blake (Temperature and Humidity Monitor), fill-up the form below. After filling the form you will receive an email which will contain further details.

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