with current output 4-20mA
Humidity transmitter HG421.65, respective NH421.65
Air relative humidity transducers with current output 4-20mA for two-wire connection are
available in wall-mount, duct-mount and bar types. Transmitter contains a microprocessor
based control circuitry in a durable plastic case with a connection terminal and a humidity
sensor in a bronze sintered filter.
Transmitters are also available with galvanic isolated temperature output 4-20mA and
humidity output 4-20mA. Computerized design ensures maximum long term stability,
temperature compensation of the humidity sensor and fail indication.
State-of-the-art capacitive polymer sensor ensures excellent calibration long term
stability, inertia against water and condensation. Transmitters are designed for use in
non-aggressive environment.
APPLICATIONS - measuring and control of air relative humidity at:
- - warehouses
- - glasshouses
- - manufacturers
- - museums, archives, galleries
- - air-conditioned rooms
- - weather stations
| COMMON TECHNICAL PARAMETERS | |
|---|---|
| Relative humidity measuring range: | 0 to 100% |
| Accuracy: | ±2.5% relative humidity from 5 to 95% at 23°C |
| Current output of relative humidity: | 4-20mA linearly corresponds 0% -100% relative humidity, see table |
| Accuracy of temperature output (transducers NH421.65xxx): |
±0.4°C from -20 to +50°C ±0.8% from reading over +50°C ±0.6°C below -20°C |
| Operational temperature range of the case with electronics: | -30 to +80°C |
| Range of temperature compensation of humidity sensor: | -30 to +105°C |
| Filtering ability of sintered bronze sensor cover: | 0.025mm |
| Protection of the case with electronics: | IP65 |
| Power: | 9-30Vdc |
| Warranty: | two years |
Transducers are available in the following types:
| Type | Measured value | Operating temperature range | Temperature output | Length | Note | Manual in pdf format |
|---|---|---|---|---|---|---|
HG421.65
|
RH | -30 to +80°C | - | 67mm | outdoor, dimensions |
|
HG421.65-150
|
RH | -30 to +105°C* | - | 150mm | duct mount, dimensions |
|
HG421.65-700
|
RH | -30 to +105°C* | - | 700mm | bar type, dimensions |
|
NH421.65
|
RH+T | -30 to +80°C |
4-20mA/ -30 to +80°C |
67mm | outdoor, dimensions |
|
NH421.65-150A
|
RH+T | -30 to +105°C* |
4-20mA/ -30 to +80°C |
150mm | duct mount, dimensions |
|
NH421.65-150B
|
RH+T | -30 to +105°C* |
4-20mA/ 0 to +150°C |
150mm | duct mount, dimensions |
|
NH421.65-700A
|
RH+T | -30 to +105°C* |
4-20mA/ -30 to +80°C |
700mm | bar type, dimensions |
|
NH421.65-700B
|
RH+T | -30 to +105°C* |
4-20mA/ 0 to 150°C |
700mm | bar type, dimensions |
|
* 105°C only at the end of measuring tip with the limitation accordingly to the Working range graph. Near plastic case with electronics and terminals maximum temperature is +80°C.
Figure: Working range of humidity sensor
Included accessory:
Included is a calibration certificate from the manufacturer - Comet, plastic gland for direct mounting of the bar and duct type transmitters to a 29mm diameter hole.
| OPTIONAL ACCESSORY | ||
|---|---|---|
|
F0000 | spare sintered bronze sensor cover with thread for measuring of temperature and humidity of polluted air. Filtering ability of the cover is 0.025mm. |
|
F5100 | plastic sensor cover with thread for measuring of temperature and humidity of clean indoor spaces. |
|
PP4 | flat plastic circular flange for duct mounting |
|
PP90 | right-angled stain-less steel flange for wall mounting |
|
accessory for calibration and adjustment of humidity by the user | |
Figure: Interconnection terminals
terminal +I current loop output 4-20mA, power voltage positive pole (typically
+24Vdc)
terminal -I ground (GND), power voltage negative pole
Figure: Typical application circuitry
Calculation of minimum power voltage Uss for proper operation:
Uss min >Uo min + Imax * Rz,
where Uo min=9V
Imax...approximately 20mA
Rz...sensing resistor (shunt)
Transmitters are directly compatible with sixteen channel Comet monitoring systems MS2+, MS3+, MS4+.