RH-Combo-Remote-Probe-Temp-Transmitter

Supported Applications

The ACI Relative Humidity with Temperature Remote Probe series is a combination transmitter whose sensing probe is mounted on a cable harness, separating the sensor from the transmitter enclosure. This lets the capacitive humidity and temperature probe be placed exactly where measurement is needed while the electronics are wired at a convenient location.

With a thermoset polymer capacitive sensing element and a hydrophobic filter, the series is suited to clean rooms, process control, environmental chambers, stability chambers, pharmaceutical labs, and other remote sensing applications. The remote probe uses 304 Series Stainless Steel and PVC, and the transmitter drives electronic controllers through a 4 to 20 mA or selectable voltage output.

Operating Conditions & Performance

The RH measurement range is 0 to 100%, with an operating range of 0 to 95% RH, non-condensing. At the reference condition, RH accuracy is ±1% over a specified 20% range between 20 to 90% RH, or ±2% or 3% from 10 to 95%. The capacitive RH element responds in 20 seconds typical (T63), while the platinum RTD responds in 8 seconds nominal, and RH stability is less than 2% drift over 5 years.

Temperature accuracy is ±0.2% for temperature spans below 260 °C (500 °F) and ±0.5% for larger spans. The transmitter is powered from 8.5 to 32 VDC (reverse polarity protected) at 25 mA minimum, and for the 4 to 20 mA output with a 250 Ω load it accepts 15 to 40 VDC or 18 to 28 VAC.

• Outputs: 4 to 20 mA (2-wire, loop powered), 0 to 5 VDC or 0 to 10 VDC, and a temperature output of 1 to 5 VDC or 2 to 10 VDC.
• Output load: 700 Ω maximum on 4 to 20 mA, or 4 kΩ minimum on the voltage outputs.
• Operating temperature: -40 °C to 60 °C (-40 °F to 140 °F); storage -40 °C to 65 °C (-40 °F to 149 °F).
• Enclosure: IP66/NEMA 4X polystyrene, measuring 93.98 mm (3.70 in) wide by 78.99 mm (3.11 in) high by 56.07 mm (2.21 in) deep.
• Wiring: polarity-sensitive screw terminal blocks with the shield grounded at the transmitter only.
• Approvals: CE, UKCA, RoHS2, and WEEE.

Each transmitter is calibrated at 22 °C (71 °F) nominal. To protect the sensor filter during wet or wash-down processes, a black rubber cap accessory is available.

Configuration Options

Every model in this series shares the capacitive RH sensing element, hydrophobic filter, matched 1K RTD, and 4 to 20 mA output in a remote-probe NEMA 4X package. Models differ by accuracy grade, remote probe cable length, and transmitter output.

Accuracy Grade

The RH1, RH2, and RH3 codes select accuracy: RH1 is ±1% over a specified 20% range between 20 to 90% RH, RH2 is ±2%, and RH3 is ±3%.

Remote Probe Length

The RP2 configuration is offered with wiring harness lengths of 3', 6', 10', and 20', so the sensing probe can reach into ducts, chambers, or enclosed spaces at a distance from the transmitter.

Temperature Element

Models use the matched TTM1K element with factory NIST calibration, and a TT1K version is also offered; the default NIST certificate is 3 points, with a 5 point certificate available.

Key Product Differences

A catalog number is assembled from the A/ prefix, the accuracy grade, the TTM1K element, the RP2 remote-probe configuration and length, the 4X enclosure, the transmitter output, and the calibrated span. For example, A/RH2-TTM1K-RP2-6'-4X-4 pairs a ±2% RH sensor with a 6' remote probe.

Representative configurations include:

• A/RH1-TTM1K-RP2-3'-4X-4 — ±1% RH accuracy with a 3' remote probe.
• A/RH2-TT1K-RP2-10'-4X-4 — ±2% RH accuracy with a 10' remote probe.
• A/RH3-TTM1K-RP2-20'-4X-4 — ±3% RH accuracy with a 20' remote probe.

For matched TTM models, a 5-point NIST certificate can be specified by adding -5PTNIST to the end of the part number.