3-Channel Industrial IoT Wireless Thermocouple Temperature Sensor

01Overview

The NCD 3-Channel Industrial IoT Wireless Thermocouple Temperature Sensor is a long-range wireless transmitter that measures temperature on three independent K-Type thermocouple channels. Each channel uses a K-Type probe with integrated hot- and cold-junction compensation, so Atrium receives a fully corrected temperature value per channel. Readings are transmitted at user-defined intervals over a long-range wireless mesh to an Atrium IIoT Gateway. The wireless module is available in three frequency options — 900 MHz (North & South America), 868 MHz (Europe), and 2.4 GHz (worldwide) — selected at time of order. Typical applications include food-storage monitoring, HVAC, industrial boilers and ovens, liquid temperature sensing, and concrete curing.

What’s in the Box

• 3-Channel Wireless Thermocouple Sensor with long-range wireless module — 900 MHz (North & South America), 868 MHz (Europe), or 2.4 GHz (worldwide), selected at order
• 3 × default K-Type thermocouple probes — 1 m cable, 24 AWG, rated to 260°C (500°F) — included when ordered with probes (upgradeable; longer cables optional)
• 3 × K-Type thermocouple connectors
• 1 × D-cell (LR20) lithium battery with supercapacitor (installed; power switch in OFF position for shipping)
• Mounting hardware

02Specifications

Full technical specifications for the 3-Channel Wireless Thermocouple Sensor (PR55-19B).

Thermocouple Probes & Ranges

Each channel ships with a standard K-Type probe. NCD stocks two K-Type probe options for this sensor — a standard probe for general use and a high-temperature probe for hot processes:

03Prerequisites

Before installing this sensor, make sure you have the following in place.

Hardware Required

• NCD Atrium IIoT Gateway — powered on and connected to your local network
• 3-Channel Wireless Thermocouple Sensor (this unit) with its K-Type probes and connectors
• 1 × D-cell (LR20) lithium battery with supercapacitor (included, switch in OFF position for shipping)

Software / Network

• A current version of Atrium running on your gateway
• A computer or mobile device on the same local network as the gateway
• A modern web browser (Chrome recommended)

04Mounting & Installation

The enclosure supports both wall-mounting and magnet mounting. Mount the electronics enclosure in an accessible, ambient location and route each thermocouple probe into the zone you want to measure.

Powering On

1. 1
   Open the enclosure

   Remove the four screws securing the enclosure lid and lift the cover.
2. 2
   Power on the sensor

   The D-cell battery is pre-installed, but the 3-position power switch ships in the middle OFF position. Slide it to Battery to run on the internal D-cell, or to External if you are powering the unit from the external supply. After a few seconds the LED will blink once, pause briefly, then blink twice quickly — this confirms successful power-on.
3. 3
   Close and seal the enclosure

   Replace the lid and tighten all four screws evenly to maintain the enclosure seal. Position the antenna upright for best signal strength.

M12 Connector Wiring

The three thermocouple probes connect through the 7-pin M12 connector. Each channel uses a pair of pins — +Yellow and −Red — and pin 7 is not used. This pinout is the same for all thermocouple types.

Connecting the Thermocouple Probes

Each K-Type probe connects to one of the three thermocouple inputs. Match the polarity markings on the connector — K-Type connectors are keyed so they only mate one way. Note which physical input maps to which channel (Channel 1, 2, 3) so your Atrium metric labels match the probe locations. Route each probe so its tip sits in the zone you want to measure, keeping the enclosure in cooler ambient air.

Mounting the Enclosure

• Wall-mount: Use the pre-drilled mounting tabs on the enclosure base. Secure with appropriate fasteners for your surface material, with the probe entries facing down.
• Magnet-mount: The enclosure base accepts a magnetic mounting plate. Attach to any ferrous surface — ideal for equipment frames, panels, ovens, and ductwork.

05Pairing with Atrium

Once powered on, the sensor begins transmitting over the long-range wireless mesh immediately. Atrium detects it automatically. By default, new sensors are held as pending (blacklisted) until confirmed — the setup wizard whitelists them and begins logging telemetry. No radio pairing or pre-registration is required. A short guided wizard walks you through onboarding.

1. 1
   Power on and close the enclosure

   Flip the power switch to ON, then close the lid. Within one transmission interval (up to 10 minutes at the default 600-second delay), Atrium will detect it.
2. 2
   Open Atrium and go to Sensors

   Navigate to your gateway’s local address (e.g. http://ncd-[last-4-of-MAC].local) and click Sensors in the top navigation. A banner shows “X sensors need setup” with detected sensors grouped by type. Your sensor appears under the Thermocouple sensor type.
3. 3
   Launch the sensor setup wizard

   Click Set Up on the sensor in the banner to open the per-sensor Sensor Details wizard. Use Save & Next to step through each field, Save to commit without advancing, or Skip to onboard manually later.
4. 4
   Select sensors to set up

   The Set Up Your Sensors step lists all detected sensors with checkboxes, pre-selected by default. Deselect any you don’t want to add, then click Set Up [X] Sensors.
5. 5
   Name and locate the sensor

   Click the sensor in the Sensors table to open its configuration. On the Sensor Meta tab, enter a Sensor Name, Asset, and Location. See Section 6 for full details.

06Sensor Meta

The Sensor Meta tab controls how Atrium identifies and tracks this sensor. Access it via Sensors → [your sensor] → Configure → Sensor Meta.

07Metric Configuration

The Metrics tab lets you configure conversion formulas, units, custom labels, and dashboard visibility for each data channel. Access it via Configure → Metrics.

This sensor exposes one temperature metric per thermocouple channel. Each value is cold-junction-compensated on-board, so Atrium receives a corrected reading:

Custom Conversion Formulas

Each metric supports a custom conversion formula using value as the variable name. Leave the formula as value or blank to display raw data. Examples:

value * 9/5 + 32       // Convert degrees C to F manually
value + 0.5            // Apply a calibration offset to a channel
value * 1.0            // Pass the raw value through unchanged

Custom Labels & Visibility

Each metric can be assigned a Custom Label (e.g. “Inlet Temp”, “Mid Temp”, and “Outlet Temp” for the three channels) that replaces the default metric name throughout Atrium. Unchecking Visible on Dashboard hides that metric’s card and chart without deleting data — useful if you are only using one or two of the three channels.

08Hardware Settings

Hardware settings control the sensor’s on-board configuration — transmission interval, network addressing, and node identity. Changes are staged in Atrium and pushed to the sensor on its next check-in. Access via Configure → Sensor Configuration. Default values shown below are loaded from the NCD config-options API and may vary by firmware version — confirm against your unit.

Thermocouple Settings

In addition to the network and timing settings above, the Sensor Configuration tab exposes thermocouple-specific measurement options. Defaults are loaded from the config-options API and may vary by firmware.

Adjusting the Transmission Interval

1. 1
   Go to Sensor Configuration

   Navigate to Sensors → [your sensor] → Configure → Sensor Configuration.
2. 2
   Update the Delay value

   Enter your desired interval in seconds. Minimum recommended value is 60 seconds.
3. 3
   Click Save Hardware Settings

   The new value is staged and will be pushed to the sensor on its next transmission.
4. 4
   Update the Report Interval in Sensor Meta

   Update the Report Interval on the Sensor Meta tab to match your new Delay value so offline detection stays accurate.

A shorter Delay increases data frequency and draws more power; a longer Delay extends battery life. The sensor delivers up to 5 years of battery life depending on configuration. To estimate battery life for your exact transmission interval and environment, use NCD’s battery life calculator. For continuous high-frequency monitoring, run the sensor on an external power supply.

09Temperature Units

Atrium provides a global temperature display unit setting that controls how temperature readings appear across the entire interface — all sensors, dashboards, alerts, and reports, including all three channels of this sensor.

1. 1
   Open Gateway Settings

   Click Settings in the top navigation to open Gateway Configuration.
2. 2
   Select Temperature Display Unit

   Under Temperature Display Unit, toggle between °C and °F. This applies immediately to all temperature readings across Atrium.
3. 3
   Save Configuration

   Click Save Configuration at the bottom of the page to apply the change.

10Sensor Dashboard

The Sensor Dashboard provides a real-time and historical view of all data from this sensor. Access it by clicking the sensor in the Sensors list and selecting Dashboard.

Live Metrics

Time Range & Charts

Use the time range selector to view historical data for the last hour, 6 hours, 24 hours, 7 days, or 30 days. A custom date/time range is also available. Each metric has its own interactive chart — drag to zoom into a time window, double-click to reset.

Mesh Route Map

Click View Map in the Mesh Route Map panel to visualize how this sensor’s data routes through the wireless mesh to reach the gateway. Useful for diagnosing signal path issues in multi-sensor deployments.

Interactive Preview

The panel below simulates the Atrium Sensor Dashboard for this 3-Channel Thermocouple sensor. Data updates every 5 seconds to demonstrate the live monitoring experience.

11Setting Alerts

Atrium uses a Triggers & Actions model for alerting. A Trigger defines the threshold condition on a metric. An Action defines what happens when all triggers fire simultaneously (e.g. send an email or activate a relay output). Navigate to Alerts in the top navigation (the page is titled Alerts & Actions) to configure.

Creating a Trigger

1. 1
   Go to Alerts → Triggers

   Click + New Trigger to open the Create Trigger form.
2. 2
   Configure the trigger

   Select the Device, Metric (e.g. temperature_1, temperature_2, or temperature_3), Condition (Above or Below), and Threshold value. The optional Hysteresis field (shown as Reset At in the trigger table) prevents repeated firing when the value oscillates near the threshold. Click Create Trigger.

Creating an Action

1. 1
   Go to Alerts → Actions

   Click + New Action. Actions link one or more triggers to a response — when all assigned triggers fire simultaneously, the action executes.
2. 2
   Assign triggers and configure the response

   Select the trigger(s) to watch and configure the notification (e.g. email) or relay output. Email must be configured in Settings → Gateway Configuration for email actions to work.

12Exporting Data

All sensor data can be exported to CSV directly from the Sensor Dashboard for use in spreadsheets, reporting tools, or other analysis software.

1. 1
   Open the Sensor Dashboard

   Navigate to the sensor and click Dashboard.
2. 2
   Select a time range

   Choose the time range you want to export using the selector at the top of the dashboard.
3. 3
   Click “CSV” on the desired metric

   Each metric chart has a CSV download button. Click it to download a timestamped CSV of that channel’s data for the selected time range. Export each channel separately.

13Product Notes

Reference information for ordering and accessories. Purchase this sensor at its store.ncd.io product page.

Buy Now on store.ncd.io →

14Troubleshooting

Common issues and their solutions.

Sensor not appearing in Atrium

• Confirm the power switch is ON and the LED blinked (1 blink, pause, 2 quick blinks) on power-up.
• Verify the sensor’s Network ID matches the gateway’s Network ID (default: 7fff).
• Move the sensor closer to the gateway to rule out range issues — test within 10 feet first.
• Check that the Atrium gateway is powered on and connected to your network.

Sensor showing as Offline in Atrium

• Verify the Report Interval in Sensor Meta matches the Delay in Sensor Hardware Settings (both default to 600).
• Check the battery percentage on the last received reading — replace the D-cell battery if below 10%.
• Check the RSSI value — readings consistently above 75 dBm may indicate marginal signal (higher values = weaker signal in Atrium); consider repositioning the sensor or gateway.

A temperature channel reads incorrectly or shows no value

• Confirm the probe for that channel is fully seated in its K-Type connector and matched to correct polarity.
• Verify the probe is not exposed beyond its 260°C (500°F) rating — over-temperature causes drift and permanent damage.
• Confirm the Temperature Display Unit in Gateway Settings is set to your preferred unit.
• A disconnected or faulty probe will not return a valid reading — swap probes between channels to confirm whether the fault follows the probe or the channel.

Hardware settings not updating on sensor

• Settings are staged and applied on the sensor’s next check-in. Wait one full transmission interval (up to 10 minutes at the default 600-second Delay) after saving.
• Confirm the sensor is actively transmitting by checking the Last Heard timestamp on the dashboard.

15Factory Reset

A factory reset restores the sensor’s wireless module to default settings. This is useful if the sensor is not being detected by a gateway, or if you are redeploying it to a new network. The magnetic switch method is recommended for sealed enclosures — no disassembly required.

Option A — Magnetic Switches (no disassembly)

1. 1
   Trigger the RESET switch

   Hold a magnet near the RESET magnetic switch, then move it away.
2. 2
   Wait 1 second

   Allow approximately 1 second before proceeding.
3. 3
   Hold the CFG switch for 20 seconds

   Hold the magnet near the CFG magnetic switch for approximately 20 seconds, then move it away. The hold must exceed 15 seconds to trigger a factory reset — a shorter hold will only enter Configuration Mode.
4. 4
   Wait 3–5 seconds

   Allow 3–5 seconds for the reset to complete.
5. 5
   Trigger the RESET switch again

   Hold the magnet near the RESET switch once more, then move it away. This returns the sensor to normal operation.

Option B — Physical Buttons (requires opening enclosure)

1. 1
   Open the enclosure

   Remove the four screws and lift the lid to expose the PCB.
2. 2
   Press and release the RESET button

   Press and release the RESET button on the PCB.
3. 3
   Wait 1 second, then hold CFG for 20 seconds

   Wait approximately 1 second, then press and hold the CFG button for approximately 20 seconds. The hold must exceed 15 seconds to trigger a factory reset. Release the button when done.
4. 4
   Wait 3–5 seconds

   Allow 3–5 seconds for the reset to complete.
5. 5
   Press RESET, then close the enclosure

   Press and release the RESET button to return the sensor to normal operation. Replace the lid and re-secure the four screws.