HU-226 is an extremely fast, stable and accurate humidity/temp
sensor designed for harsh environments. The polymer humidity
capacitance sensor is protected with an ePTFE (expanded Teflon) filter media. The Teflon protected cross-linked capacitive humidity sensor is not affected by prolonged exposure to condensing humidity, harsh environments, contaminants, fog or other extreme environmental conditions. Each
is individually calibrated in an environmental test chamber
to meet or exceed NIST traceable ± 2% or ± 3%
accuracies. The HU-226 is temperature compensated for -30°F (-35°C) to +130°F (55°C) operation
with negligible error. Field selectable outputs, and fully
temperature compensated NIST traceable accuracy, non-interacting
zero and span adjustments, NEMA-4 (IP-65) steel enclosure with
external mounting bracket, short circuit and reverse polarity
protected output, and a liberal five year warranty are some
of the features which make the HU-226 the industry's highest
performance, most reliable humidity/temp sensor..
HU-226 incorporates a cross-linked bulk polymer capacitive humidity sensor
and precision NTC thermistor, platinum or balco RTD temperature sensor.
Both temperature and humidity sensors are immune to most
contaminants and at the same time provide a stable, repeatable,
accurate humidity and temperature measurement with negligible
hysteresis. The sensing elements are not affected by condensation.
In fact, the probe may be immersed in distilled water without
degrading the calibration accuracy. The HU-226 utilizes sophisticated
integrated circuits to provide a high level, fully conditioned,
and temperature compensated humidity output. The thermistor
temperature sensors are available with more than 16 different
industry standard resistance to temperature curves offering
compatibility to most if not all control systems. All thermistor
sensors offer ±0.2°C interchangeability/accuracy and strictly conform to industry standard R/T
curves. The platinum RTDs are available with 100 ohm
or 1000 ohm DIN 43760 standards with ±0.12%
accuracy at 0°C. All temperature sensors have more than
3.0 mW/°C heat dissipation constant.
VDC output units (humidity only), two additional field selectable
options are available; dual outputs 0-5 or 0-10 VDC,
and dual unregulated supply voltages 12-35 VAC or 12-40 VDC. By merely moving a switch, one can select
output for the specific application. As far as supply voltage
is concerned, the unit automatically configures for AC or
DC and no field selection is necessary. The VDC output unit is also designed to handle
low impedance circuits. In fact, the unit can drive up to
1K ohm minimum. In this way, multiple controllers, indicators,
or other devices can be paralleled to the output without
mA output units (humidity only) function over a wide unregulated
supply voltage range: 12-40 VDC without any effect on
calibration or performance. The unit has reverse polarity
built in. As a result, it is next to impossible to damage
the unit by wiring incorrectly.
using sophisticated low dropout voltage regulators and CMOS
the mA output unit can drive very high output impedance.
In fact, with only 12 VDC supply, the unit can drive 250
ohms. At 40 VDC, the unit is capable of handling up to
a 1500 ohm load. In this way, the output loop can be tied
series to multiple controllers, indicators, and other devices
without degrading the performance.
The humidity sensor is protected by an ePTFE (expanded Teflon) filter media that incorporates a proprietary process of expanding or stretching an ultra thin Teflon sheet during the manufacturing process to create less than 1.0 micron (0.000039 inch) pores or holes. The hydrophobic and oleophobic characteristics of Teflon force moisture, condensation and other contaminants to form a bubble larger than the pore size, and the surface tension of the Teflon stops the water or other contaminants from passing through the filter media, thereby protecting the sensing element. However, air with absorbed moisture can easily penetrate the filter media.
HU-226 incorporates a rugged
NEMA-4 (IP-65) fully gasketed, dust proof, and splash proof
enclosure. The enclosure has an external mounting bracket
to facilitate field installation. A ½'' (.875''/22.25
mm diameter) knock-out for conduit connection is also provided.
A liquid tight cable connector is supplied if the unit is
not being hard wired. Once installed, the enclosure maintains
its environmental rating and protects the electronics and
the sensing element from condensation, corrosive contaminants
and other environmental pollutants. The enclosure also has
additional features for ease of installation including unpluggable
terminal block, and easily accessible
zero and span trimmers.