Manufacturing cameras requires strict environmental control to ensure quality and reliability. Dust contamination can damage sensitive components, while low humidity increases the risk of electrostatic discharge (ESD) harming image sensors. Today, factory conditions are mostly monitored electronically, but historically analog devices were used for these measurements. Rediscovering old photos of past instrumentation reveals how far we’ve come—leading to more consistent and high-performing cameras today.

The device shown below was once a key tool in our factory: a thermohygrograph, which tracked both humidity and temperature. Data was recorded on paper wrapped around the cylindrical core visible in the left part of this photo.

Left panel shows the entire thermohygrograph; center highlights the cylinder’s winding mechanism, while right side displays hair bundles and a bimetallic spiral.

To keep the device running, you actually had to wind it manually—no batteries needed! This made it an eco-friendly solution for its time.

Humidity was measured using hair bundles, which expand in high moisture conditions and contract when dry. Interestingly, this method of humidity detection dates back to 1783!

Temperature measurement relied on a bimetallic spiral. Different metals expand at varying rates; their movement converts temperature changes into mechanical motion.

Modern equipment is far more compact, as seen below:

Last Updated: 2025-09-04 21:15:57