Mounted through a duct wall, this transmitter measures relative humidity in the air stream to ±1% accuracy using a thermoset polymer capacitive element behind a hydrophobic filter. A matched 10,000 ohm Type II thermistor shares the housing, so humidity and temperature reach the controller from a single duct penetration. Field-selectable outputs cover 0-5 and 0-10 V DC and 4-20 mA.
Mounted through a duct wall, this transmitter measures relative humidity in the air stream to ±1% accuracy using a thermoset polymer capacitive element behind a hydrophobic filter. A matched 10,000 ohm Type II thermistor shares the housing, so humidity and temperature reach the controller from a single duct penetration. Field-selectable outputs cover 0-5 and 0-10 V DC and 4-20 mA.
The ACI Relative Humidity with Thermistor Duct Series utilizes a thermoset polymer capacitive sensing element with a factory fitted hydrophobic filter to improve its moisture resistance. The sensing elements multilayer construction also provides excellent resistance in applications where dust, dirt, oils and common environmental chemicals are found. The RH duct sensors include on board DIP switches which allow the user to select the desired output signal and can be powered by AC or DC power sources. Each unit also contains 0%, 50%, and 100% test options to verify that the transmitter is both working and wired properly.
Features
Applications
| RH Measurement Range | 0 to 100% |
| RH Accuracy @ 77°F (25°C) | ± 1% over 20% RH Range between 20 to 90% | ± 2%, or 3% from 10 to 95% |
| RH Stability | Repeatability | Sensitivity | Less than 2% drift / 5 years | 0.5% RH | 0.1% RH |
| Thermistor Accuracy 32 to 158°F (0 to 70°C) | ± 0.36°F (0.2°C) |
| RH Output Load Resistance | 4 to 20 mA: 700 Ohms maximum | 0 to 5 V DC or 0 to 10 V DC: 4K Ohms Minimum |
| RH Output Signal | 2-wire: 4 to 20 mA (Factory Default) | 3-wire: 0 to 5 or 0 to 10 V DC and 4 to 20 mA (Field Selectable) |
| RH Response Time (T63) | 20 Seconds Typical |
| RH Transmitter Stabilization Time | 30 Minutes (Recommended time before doing accuracy verification) |
| Thermistor Sensor Response Time (T63) | 10 Second nominal |
| RH Supply Current (VA) | Voltage Output: 8 mA maximum (0.32 VA) | Current Output: 24 mA maximum (0.83 VA) |
| RH Supply Voltage (Reverse Polarity Protected) | 0 to 5 V DC: 12 to 40 V DC / 18 to 28 V AC | 0 to 10 V DC: 18 to 40 V DC / 18 to 28 V AC |
| Thermistor Power Dissipation Constant | 3 mW/°C |
| RH Sensor Type | Capacitive with Hydrophobic Filter |
| Lead Wire Length | Conductor Size | 14" (35.6 cm) | 22 AWG (0.65 mm) |
| RH Connections | Wire Size | Screw Terminal Blocks (Polarity Sensitive) | 16 (1.31 mm2) to 26 AWG (0.129 mm2) |
| RH Terminal Block Torque Rating | 4.43 to 5.31 lb-in (0.5 to 0.6 Nm) |
| Operating RH Range | 0 to 95% RH, non-condensing (Conformally Coated PCB's) |
| Nominal Thermistor Resistive Output @ 77°F (25°C) (Lead Wire Colors) | 10KΩ (White/Green) |
| Operating Temperature Range | -40 to 140°F (-40 to 60°C) |
| Storage Temperature Range | -40 to 149°F (-40 to 65°C) |
| Product Dimensions (L x W x H) | 10.20 x 4.10 x 3.90" (259.1 x 104.1 x 99.1 mm) |
| Product Weight | 0.70 lbs (317 g) |
| Agency Approvals | UKCA, CE, RoHS2, WEEE |
| RH Measurement Range | 0 to 100% |
| RH Accuracy @ 77°F (25°C) | ± 1% over 20% RH Range between 20 to 90% | ± 2%, or 3% from 10 to 95% |
| RH Stability | Repeatability | Sensitivity | Less than 2% drift / 5 years | 0.5% RH | 0.1% RH |
| Thermistor Accuracy 32 to 158°F (0 to 70°C) | ± 0.36°F (0.2°C) |
| RH Output Load Resistance | 4 to 20 mA: 700 Ohms maximum | 0 to 5 V DC or 0 to 10 V DC: 4K Ohms Minimum |
| RH Output Signal | 2-wire: 4 to 20 mA (Factory Default) | 3-wire: 0 to 5 or 0 to 10 V DC and 4 to 20 mA (Field Selectable) |
| RH Response Time (T63) | 20 Seconds Typical |
| RH Transmitter Stabilization Time | 30 Minutes (Recommended time before doing accuracy verification) |
| Thermistor Sensor Response Time (T63) | 10 Second nominal |
| RH Supply Current (VA) | Voltage Output: 8 mA maximum (0.32 VA) | Current Output: 24 mA maximum (0.83 VA) |
| RH Supply Voltage (Reverse Polarity Protected) | 0 to 5 V DC: 12 to 40 V DC / 18 to 28 V AC | 0 to 10 V DC: 18 to 40 V DC / 18 to 28 V AC |
| Thermistor Power Dissipation Constant | 3 mW/°C |
| RH Sensor Type | Capacitive with Hydrophobic Filter |
| Lead Wire Length | Conductor Size | 14" (35.6 cm) | 22 AWG (0.65 mm) |
| RH Connections | Wire Size | Screw Terminal Blocks (Polarity Sensitive) | 16 (1.31 mm2) to 26 AWG (0.129 mm2) |
| RH Terminal Block Torque Rating | 4.43 to 5.31 lb-in (0.5 to 0.6 Nm) |
| Operating RH Range | 0 to 95% RH, non-condensing (Conformally Coated PCB's) |
| Nominal Thermistor Resistive Output @ 77°F (25°C) (Lead Wire Colors) | 10KΩ (White/Green) |
| Operating Temperature Range | -40 to 140°F (-40 to 60°C) |
| Storage Temperature Range | -40 to 149°F (-40 to 65°C) |
| Product Dimensions (L x W x H) | 10.20 x 4.10 x 3.90" (259.1 x 104.1 x 99.1 mm) |
| Product Weight | 0.70 lbs (317 g) |
| Agency Approvals | UKCA, CE, RoHS2, WEEE |
