Developing a Temperature and Humidity Diagnostic System for the Optical and Electronic Infrastructure of a Primary Caesium Quantum Clock

Caesium quantum clocks, pivotal in defining the SI second since the 13th General Conference on Weights and Measures in 1967, rely on intricate electronic and optical systems for precise timekeeping. Ensuring the accuracy of these systems requires monitoring and controlling environmental parameters like temperature and humidity, as fluctuations can lead to errors and potential damage. This paper presents the development of a diagnostic system using an Arduino UNO connected to a DHT11 sensor and ESP8266 Wi-Fi module to continuously monitor and transmit environmental data. The collected data is analyzed to maintain optimal operating conditions for the quantum clock infrastructure. Implementations using the IoT platform ThingSpeak demonstrate the system's capability for real-time data visualization and analysis. Statistical analysis of sampled data over a 30-minute interval shows a mean temperature of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$23.45^{\circ}\mathrm{C}$</tex> and a mean humidity of 51.30%, with a strong correlation coefficient of 0.99 between the two parameters. A linear regression analysis further supports this relationship, indicating that for every <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1^{\circ}\mathrm{C}$</tex> increase in temperature, humidity increases by approximately 5.11%. This diagnostic system not only ensures environmental stability but also aids in preventing inaccuracies in timekeeping, enhancing the reliability of caesium quantum clocks.