Standard Humidity Probes
 

Precon offers the following products for the building control industry.  They are available in current form in small and large volumes and can also be customized for a specific application. HW Series 5% RH Sensor/Transmitter 3% Humidity Transmitter & Optional Temperature Transmitters Model H-31K 3% Air Humidity Transmitters are specifically designed for user in HVAC/BAS applications. These instruments measure relative humidity from 0% to 100%. The standard two-wire, 4-20 mA output provides low cost humidity monitoring for building control. The RH transmitter is available with thermistor or RTD temperature sensors or a 4-20 mA rangeable temperature transmitter. H-31K models available in room, duct, and OSA mounting styles. FEATURES 0% to 100% RH measurement ±3% accuracy (5% to 95% RH) Two-Wire, 4-20 mA output White plastic design SPECIFICATIONS Sensing Element  Capacitive Polymer   Transmitter 4-20mA, 675ohm @ 24V (HD31K & HO31K only) Accuracy     ±3% RH @ 77°F (25°C), 5% to 95% RH Supply Voltage 18 - 35 VDC Temp Effect Temperature compensated with 0.005% RH per °F (0.01% per °C) Ambient temp -20° to 140°F (-28° to 60°C) Long-term stability <±1% drift per year, typcial Storage temp -58° to 185°F (-50° to 85°C) Output humidity Two-wire, loop-powered, 4-20 mA = 0% to 100% RH linear Max load impedance (Supply voltage - 12 VDC) /0.02 i.e. 600ohm@24VDC Output temp Two-wire, loop-powered, 4-20 mA Connections Screw terminals for loop termination Temp range limits -30° to 250°F (-34° to 121°C), min span of 40°F (22°C) Enclosure White plastic Optional temp Thermistor Type 3, 21, 22, 24, 27, 42 Weight 1.2 lb (0.55 kg) RTD Type 81, 85, 91     HD Series 3% Duct / Outside Air RH Sensor / Transmitter Model HD30K Duct and HO30K Outside Air Humidity Transmitters have been specifically designed for use in HVAC/BAS applications. These instruments measure relative humidity from 0% to 100%. The standard two-wire, 4-20 mA output provides low cost duct and outside air monitoring for building control. Both duct and outside air RH transmitters are available with thermistor or RTD temperature sensors or with a 4-20 mA rangeable temperature transmitter. FEATURES 0% to 100% RH measurement ±3% accuracy (5% to 95% RH) Two-wire, 4-20 mA output RH Optional temperature thermistor Optional temperature RTD Optional temperature 4-20 mA SPECIFICATIONS Sensing Element  Capacitive Polymer   Operating temp -20° to 185°F (-28° to 60°C) Accuracy     ±3% RH @ 77°F (25°C), 5% to 95% RH Storage temp -58° to 185°F (-50° to 85°C) Temp Effect Temperature compensated with less than  0.005% RH per °F (0.01% per °C) Max load impedance (Supply voltage - 10 VDC) /0.02 i.e. 700 ohm @ 24 VDC Long-term stability Less than ±1% drift per year, typcial Connections Screw terminals for loop termination Output humidity Two-wire, loop-powered, 4-20 mA = 0% to 100% RH linear Enclosure Single-gang, pressure-cast aluminum weatherproof box with gasketed cover Supply Voltage 18-35 VDC Weight 1.20 lb (0.55 kg) Operating range 0% to 100% RH, 4-20 mA Optional temp Thermistor type 3, 21, 22, 24, 27, 42 RTD type 91, 81 4-20 mA, 650ohm @ 24V     KHR Series 3% Duct / Outside Air RH & temperature Sensor / Transmitter Models KHR and KHD are low cost, general-purpose humidity transmitters that utilize capacitance technology. Wide range and good accuracy make these ideal humidity transmitters for locations where ±5% RH readings are required. The sensors are designed for indoor applications where relatively stable temperature conditions exist. The sensors should not be exposed to vapors, such as acetone, that attack plastics. FEATURES Fast response Accuracy ±5% 10% to 90% Humidity span 0% to 100% 4-20 mA signal Highly stable One-year warranty SPECIFICATIONS Output range 0% to 100% Operating temp 32° to 122°F (0° to 50°C), 0% to 100% RH, noncondensing Accuracy     ±5% (10% to 90% RH) Transmitter output 4-20 mA, DC two-wire (0% to 100%) Linearity ±3% Power requirement 18-35 VDC Hysteresis 3% (10% to 90% RH) Max external load 600ohm @ 24 VDC Temp dependence 0.2% RH per °C Weight 1 lb (0.45 kg)   Precon’s package includes: Low Cost OEM supplier Six-Sigma quality testing standards Standard and custom products Fast response time Volume production capability 35 years of manufacturing experience Made in the USA  Applications Food Processing Equipment Pool and Spa Systems Industrial Process Control Remote System Monitoring Semiconductor Fabrication Commercial Equipment Building Automation