Nickel-Probe-Only

Supported Applications

The ACI Nickel Probe Only Series is a bare single-point Nickel RTD temperature probe for use with electronic controllers in commercial heating and cooling building-management systems. It features a ¼" diameter stainless-steel probe with two 22 AWG etched-Teflon colored lead wires, supplied without an enclosure so it can be integrated into custom mountings, ducts, pipes or user-supplied thermowells.

The probe monitors air temperature and should not be fully submerged in water. Its etched-Teflon leads are resistant to oil, moisture, acids, sunlight and abrasion, and ACI's double-encapsulation process protects the element from moisture while improving thermal response. As with all such sensors, its wiring must never be run in a conduit carrying line voltage.

Operating Conditions & Performance

The sensor is a Nickel RTD with a positive-temperature-coefficient (PTC) curve, a nominal output of 1000 Ohms at 21.1°C and Red/Red leads. It conforms to DIN 43760 with a temperature coefficient of 6370 ppm/°C and operates over -40 to 121°C.

Accuracy is ±1.52°C at -40°C, ±0.4°C at 0°C, ±0.17°C at 21.1°C, ±0.56°C at 54.4°C and ±1.25°C at 121°C. Response time is 8 Seconds nominal, the power dissipation constant is 0.3°C/mW in still air with a maximum operating current of 5 mA, and long-term stability is ±0.05% after 1000 Hours at 150°C.

The probe is 304 stainless steel with a 6.35 mm diameter, storage is rated -40 to 85°C, and operating humidity is 10 to 95% RH, non-condensing. The series is CE, RoHS2 and WEEE compliant and is covered by ACI's five-year limited warranty. Optional NSG heat-transfer paste is available for thermowell installation.

Configuration Options

Because the enclosure is omitted, variants differ by probe length and lead-wire option rather than by housing:

• Probe length — probes are offered in 2", 4", 6", 8", 12" and 18" lengths (each insertion length held to ± 0.13"), with no flare present on 6" and shorter probes.
• Lead-wire option — standard etched-Teflon leads or extended plenum-rated cable such as 6'CL2P and 10'CL2P for longer runs to the controller.
• NIST — an optional NIST-traceable calibration certificate.

All variants share the same Nickel RTD element, 1000 Ohms nominal output and accuracy, so length and lead type are chosen to suit the mounting depth and the wiring distance.

Key Product Differences

Models follow the scheme A/1K-NI-PO-<probe length>-<lead wire>-<NIST>, for example A/1K-NI-PO-4"-6'CL2P-NIST. The lineup includes:

• A/1K-NI-PO-2", A/1K-NI-PO-4", A/1K-NI-PO-6" and A/1K-NI-PO-8" — standard-lead probes in the shorter lengths.
• A/1K-NI-PO-12" and A/1K-NI-PO-18"-6'CL2P — longer probes, including a plenum-cable option.
• A/1K-NI-PO-4"-10'CL2P and A/1K-NI-DO-4"-10'CL2P-NIST — extended-cable variants, with NIST certification available.

The combination of probe length, lead-wire type and optional NIST certificate lets the bare Nickel RTD be specified for a wide range of OEM and retrofit temperature-monitoring installations.