The neo® Blu is Holtronic’s Bluetooth-enabled single-use temperature data logger. It combines on-device LED breach alerts with wireless data retrieval — pull a complete temperature history from the indicator to your phone without opening the package, unplugging a cable, or touching the device. One button press to start. One app to read the record.
The neo® Blu occupies a unique position in the Holtronic range: it gives you the instant visual breach alert of a neo® Penta indicator plus a full downloadable temperature log you can store, share and audit — without the bulk, cost or infrastructure of a traditional data logger.
±0.2°C precision Tighter accuracy than standard indicators verified at every configured threshold. For applications where narrow tolerance windows demand the highest confidence in the reading.
Bluetooth wireless retrieval Download the complete breach record — extent, duration, timing — from outside the package, through container walls and without line-of-sight. No cables, no proprietary readers.
100% tested & individually traceable Each neo® Blu has a unique serial number and individual calibration certificate, accessible via the QR code on the device.
On-device LED alerts Don’t need the app to make an accept/reject decision? The red Alarm LED gives an immediate visual pass/fail at the point of receipt. No phone required.
Free Holtronic app View alarm status, retrieve full logs and generate audit-ready reports on any Android device. Offline, no account, no subscription.
Read the full specifications.
Type | Single use, non reversable |
Size | 24.6mm x 44.5mm x 5.8mm ; 6g |
Low Temp Alarms | <0°C single event, 10 min · <2°C cumulative, 30 min |
High Temp Alarms | >8°C cumulative, 60 min |
Housing | Rigid Plastic |
Activation | Hold button for 3 seconds ±0.5 sec |
Sensor | Internal NTC |
Start Delay | 30 minutes ± 100ms |
Active Life | 9 months |
Shelf Life | 2 years |
Environmental | IP54 |
Operating Temperature | -20°C to 60°C |
Battery | CR2032 lithium button cell |
Temperature Accuracy | 0°C ±0.2°C · 2°C ±0.2°C · 8°C ±0.2°C |
Time Accuracy | ±15ms over 5min · ±100ms over 30min |
Sample Period | 24 sec |
Connectivity | Bluetooth Low Energy (BLE) |
LED Indicators | Power on (Green) • |
Custom threshold configurations are available for different temperature ranges and alarm durations. Contact the Holtronic team to specify a bespoke build.
Press and hold the button for 3 seconds until the green Power LED flashes three times. Once activated, the
Power LED continues flashing every 8 seconds to confirm the device is running. A 30-minute start delay follows
before temperature logging begins, preventing false readings caused by handling during packing.
Fix the indicator to the product, inner pack or container and send it on its way. The neo® Blu samples
temperature every 24 seconds and logs continuously for the length of the journey. No app or network
connection needed during transit.
On arrival, press the button to interrogate the LEDs. The green Power LED confirms the device is still active. If
any temperature threshold has been breached for its set duration, the red Alarm LED flashes giving receiving
staff an instant pass/fail decision without needing a phone or reader. A blue LED flashes when Bluetooth
communication is active.
Open the free Holtronic app on any Android device and bring it within Bluetooth range of the indicator. No
need to open packaging, access a cold room or physically handle the unit. The app downloads the complete
temperature history, including every breach event’s extent, duration and exact timing.
From within the app, generate a downloadable report covering the full monitoring period. Reports are stored
locally on the device and can be shared, exported or filed into your QA and audit systems. All without an
internet connection.
The neo® Blu uses a three-LED system that communicates device status, breach alerts and wireless activity at a
glance. Unlike the neo® Penta’s lettered A–E alarm LEDs (which show exactly which threshold triggered), the neo® Blu uses a single red Alarm LED for all breach types. The detail of which threshold was crossed, and for how long, is available in the app download. The LED gives the quick visual pass/fail; the app gives the full story.
Activation Confirmed | Green Power LED flashes 3 times |
Monitoring active | Green Power LED flashes every 8 seconds |
Temperature below 0°C or 2°C | Red Alarm LED flashes every 8 seconds |
Temperature rises above 8°C | Red Alarm LED flashes every 8 seconds |
Bluetooth communication active | Blue LED flashes every 8 seconds |
Hold the button for 3 seconds until the green Power LED flashes three times. The device then enters a 30-minute start delay before temperature logging begins, giving you time to attach it and place it in position without recording handling temperatures.
The standard BL configuration watches for three events: a single dip below 0°C lasting 10 minutes or more, cumulative time below 2°C exceeding 30 minutes, and cumulative time above 8°C exceeding 60 minutes covering both a freeze event and a heat excursion on one device.
Temperature accuracy is ±0.2°C at each configured threshold — tighter than the ±0.5°C offered by the neo® Penta range — with time accuracy to within ±15ms over 5 minutes and ±100ms over 30 minutes.
No. The red Alarm LED on the device itself flashes if any threshold has been breached, so receiving staff can make an immediate accept/reject decision with no phone or equipment. The app adds the detail: which threshold, for how long, and when.
No. Activation, monitoring, Bluetooth data transfer, and report generation all work entirely offline. Data moves directly from the indicator to the phone over Bluetooth. No cloud account, no Wi-Fi, no subscription.
Both are single-use, but they serve different needs. The neo® Penta gives you up to five separate LED alarms for a visual-only workflow. No app, no download, just read the LEDs. The neo® Blu adds Bluetooth wireless data retrieval and app-based reporting on top of the LED alert, so you get both a quick visual check and a full downloadable temperature record for audit and QA purposes. The neo® Blu also offers tighter ±0.2°C accuracy versus the Penta’s ±0.5°C.
Scan the QR code printed on the front of the indicator. It links through to a Holtronic web page where you can view and download that unit’s individual calibration certificate.
Yes. Custom threshold and duration settings can be specified to match your product’s requirements. Contact the team to discuss a custom configuration.
The same compact footprint as every other indicator in the Holtronic neo range: 24.6mm x 44.5mm x 5.8mm and 6g. Small and light enough to attach directly to individual products.
Active life is 9 months from activation, with a 2-year shelf life before use. The CR2032 lithium cell powers continuous 24-second temperature sampling and Bluetooth communication throughout the entire monitoring period.
Tell us about your application and we’ll get a neo® Blu sample into your hands.
