Reliable, economical and compact, the EMD-2000, 3000 and 4000 Relative Humidity Sensors are ideal for humidity measurement applications that require a high degree of accuracy without calibration. These sensors offer good chemical resistance and excellent response time characteristics. The EMD sensors require a simple drive circuit and are directly solderable. All are suitable for use in a variety of OEM applications.

The EMD-2000 offers tight accuracy and exceptional chemical resistance. An HDPE filter cover protects the sensor during handling and helps keep contaminants from affecting performance.

The EMD-3000 offers high accuracy and low hysteresis. Compact size means it can fit into most existing designs where space is at a premium.

The EMD-4000 is the newest resistive RH sensor to be added to General Eastern’s popular EMD family of sensors. Compact, reliable and cost-effective, the EMD-4000 has an operating range of 20 to 99% RH and measurement accuracy as low as 3%. It is well suited for a variety of OEM applications – including data loggers, humidifiers & dehumidifiers, and automotive climate control.

EMD Series Theory of Operation

The EMD series sensors are bulk polymer RH sensors that change resistance as the relative humidity changes. Each sensor is composed of interdigitated metal fingers on a ceramic substrate with a proprietary polymer coating placed over the surface. As the ambient humidity increases, the water absorbed in the polymer increases, thus decreasing resistance. As the water is desorbed by the polymer, the resistance decreases.