1. An automatic device that controls humidity by turning a humidifier or dehumidifier on and off when moisture levels reach preset thresholds.
Usage: Technical term; commonly used in HVAC and climate control contexts.

Examples

• The hygrostat in the basement automatically activates the dehumidifier when humidity exceeds 60 percent.
• Installing a hygrostat helped prevent mold growth in the damp storage room.
• Modern thermostats often include a built-in hygrostat for integrated climate management.
• The hygrostat maintained the museum's air at exactly 45 percent relative humidity to protect the artifacts.