M381 4G Real Time Disposable Temperature and Humidity Data Logger
Full band 4G for cross border lanes, live to the H7 cloud platform
The M381 is a high precision single use recorder built on a 4G wireless network. It uploads temperature, humidity and position to the H7 cloud platform while the cargo is still moving, so an excursion sends an instant SMS to the responsible personnel rather than surfacing three days later at the delivery gate.
The housing is solid, reliable and compact. Global 4G network communication gives long communication distance, strong anti interference performance and straightforward networking, which is what makes this the model to specify for shipments that cross borders and carrier networks.
- Network
- 3G or 4G
- Accuracy
- ±0.3°C
- Memory
- 7200 readings
- Runtime
- Up to 100 days
What the M381 is built to do
Every real time logger faces the same practical question: will it still have a network when it matters? A device that reports beautifully in its home market and goes silent after the first border crossing has failed at exactly the moment the shipment became risky.
The M381 answers that with a full band 4G communication module. It is the model to specify when your cargo moves across countries, changes carriers, or travels through markets that have already begun retiring their older networks.
Why full band matters more each year
2G and 3G networks are being switched off market by market as operators reclaim spectrum for 4G and 5G. A logger tied to those older bands works fine today on some routes and simply stops working on others, with no warning and no way to tell from the device itself.
Because the M381 is full band, the same unit works across markets without compatibility checks before every new lane. For a buyer building a monitoring programme meant to last several years, that is the difference between one specification and a rolling problem.
Live data, not a post mortem
The M381 uploads to the H7 cloud platform on the interval you choose, typically every 60 or 120 minutes. From one interface your team can view live temperature and humidity, see positioning details, read alarm history, manage devices and export data. When a threshold is crossed, the platform sends an instant notification by SMS to the relevant management personnel.
Nothing to configure
Deployment is one physical action. The SIM card is installed before the unit leaves the factory, so pulling out the strip activates it. There is no parameter setting, no pairing and no app. Anyone handling the shipment can arm the device without training.
Coverage gaps do not break the record
Cold chain routes pass through tunnels, port yards and rural stretches with weak reception. Signal blind area data retransmission holds readings taken offline and sends them once coverage returns, so the curve arrives complete. Data is written to local flash memory in parallel, and the USB port produces a full PDF report at the destination regardless of what happened to connectivity.
Where it is used
The M381 suits vaccine distribution, blood transport, pharmaceutical shipments, fresh produce and containerised freight, particularly on export lanes where the cargo leaves your own network and enters someone else's.
One movement to activate
The device is ready straight out of the box. Pull out the strip to activate the built in SIM card. No parameter setting is required.
M381 full specifications
Complete communication, measurement and power specification for the M381 4G real time single use data logger.
Communication and measurement
| Type | Single use |
|---|---|
| Communications | 3G or 4G, full band |
| Location | LBS |
| Sensor 1 | Temperature and humidity, internal |
| Sensor 2 | Light, internal |
| Measurement range | -30°C to 70°C or -40°C to 70°C, 0%RH to 100%RH |
| Temperature accuracy | ±0.3°C (-10°C to 70°C), ±1°C on other ranges |
| Humidity accuracy | ±5%RH (20 to 80%RH), ±8%RH on other ranges |
| Memory | 7200 readings |
Platform, power and protection
| Cloud platform | H7 or customized |
|---|---|
| Warning | LED light, SMS or email via platform alarm |
| SIM card | Built in, installed before dispatch |
| Battery capacity | 2000 mAh or 4000 mAh |
| Waterproof class | IP65 |
| Shelf life | 1 year |
| Software upgrade | Remote platform upgrade |
| Local storage | Flash memory plus USB PDF export |
| Minimum order quantity | 5 pieces |
Positioning uses LBS, which derives location from the mobile network rather than a satellite fix. It reliably identifies the city or route segment a shipment is on, which is the level of detail that matters when deciding where to intervene.
Recording up to 100 days
Runtime depends on two things you choose at order stage: the upload interval and the battery capacity. Four variants cover the range.
| Product model | Sensor type | Upload every 60 mins | Upload every 120 mins | Battery |
|---|---|---|---|---|
| M381-T | Temperature | 30 days | 50 days | 2000 mAh |
| M381-TH | Temperature and humidity | 30 days | 50 days | 2000 mAh |
| M381-T-XL | Temperature | 60 days | 100 days | 4000 mAh |
| M381-TH-XL | Temperature and humidity | 60 days | 100 days | 4000 mAh |
Doubling the upload interval doubles the runtime without reducing what is recorded locally. For a 40 day sea leg, the XL variant at 120 minute uploads is the usual choice.
One interface for the whole fleet
Live readings, positioning details, alarm history, device management and data export, all from a browser. Custom platform integration is available on request.
Remote monitoring dashboard
Access temperature and humidity data as it arrives, review alarm information, track positioning details and manage devices from a single interface, then export whatever your quality team needs.
Records stored for 3 to 5 years
Real time data, over temperature alarm records, email and SMS alarm records and average records are retained on the platform, which matters when a claim or an audit arrives long after the shipment closed.
Data storage and download
To keep the record safe, the M381 does not rely on the cloud alone. Data is also stored locally in flash memory, so in an emergency the USB port can be connected to generate a comprehensive PDF report immediately, with no platform access needed.
M381 detailed view
Solid, reliable and compact, rated IP65 against the working environments a cold chain device actually sees.
What sets the M381 apart
High performance digital sensor
A built in digital sensor gives ±0.3°C accuracy between -10 and 70°C, with stable performance across the full working range.
Ready out of the box
No parameter setting is needed. Pull the strip to activate the built in SIM and the device starts logging and uploading straight away.
Full band 4G, global use
An embedded full band 4G communication module enables use across markets without checking carrier compatibility before every new lane.
Signal blind area retransmission
Readings taken with no coverage are held and sent once signal returns, so the data chain stays continuous through tunnels and port yards.
Instant and timed uploads
Both immediate and scheduled uploads are supported, so alarm notifications are transmitted promptly rather than waiting for the next window.
Optional low light detection
A second internal sensor can detect light, which flags an unexpected container or carton opening during transit.
IP65 waterproof design
Built to withstand the working environments a cold chain device actually meets, including condensation and washdown.
Local data export
Records can be exported to local storage through our upper computer software, or written to a PDF report through the USB port.
Where the M381 is deployed
Real time monitoring earns its cost on lanes where an excursion discovered in transit can still be acted on, and 4G earns its cost when those lanes cross borders.
Vaccine distribution
Immunisation supply crossing national borders, where a breach means a discarded batch and an SMS alert can still save it.
Blood transport
Whole blood, plasma and platelets moving between collection centre, laboratory and hospital on a tight clock.
Pharmaceutical
High value medicine held in a narrow window, where the platform alarm reaches the responsible person wherever the cargo is.
Fruit and vegetable
Fresh produce export where a few hours out of range shortens shelf life enough to change the arrival grade.
Containerised freight
Long sea legs across multiple carrier networks, where the XL variant covers up to 100 days on one charge.
Reefer container
Intermodal routes where the cargo changes hands and networks several times before it reaches the consignee.
M381 4G or M371 3G?
The two real time models share sensors, accuracy, memory and cloud platform. The deciding factor is the network available on your lanes.
| Specification | M381 | M371 | M501 |
|---|---|---|---|
| Network | 3G or 4G full band | 2G or 3G | None, USB only |
| Reporting | Live to H7 cloud | Live to H7 cloud | PDF at destination |
| Positioning | LBS | LBS | None |
| Temperature accuracy | ±0.3°C | ±0.3°C | ±0.5°C |
| Memory | 7200 readings | 7200 readings | 14400 readings |
| Alarm notification | SMS and email in transit | SMS and email in transit | In the report |
| Protection class | IP65 | IP65 | IP67 |
| Best suited to | Cross border and 4G only lanes | Domestic lanes with 3G coverage | One way export freight |
| Minimum order | 5 pcs | 5 pcs | 5 pcs |
| Product page | You are here | View M371 3G | View M501 |
If a lane runs entirely inside a market with solid 3G coverage, the M371 does the same job for less. The M381 is the right call the moment shipments leave that market.
M381 questions from buyers
What does full band 4G actually mean for my shipments?
It means the communication module supports the 4G frequency bands used across different markets rather than a single regional set. In practice, one specification travels with your cargo instead of needing a compatibility check for every new destination.
This matters because operators are progressively switching off 2G and 3G to reuse the spectrum. A device tied to older bands still works on some routes and simply goes silent on others.
Do I need to buy a SIM card or a data plan separately?
No. The SIM card is built in and installed before the device leaves the factory. Activation is a single physical action: pull out the strip. There is no account to set up, no APN to configure and no separate carrier contract to arrange.
What is the difference between the M381 and the M371?
The sensors, accuracy, memory, cloud platform and housing are the same. The difference is the communication module: the M381 uses full band 3G or 4G, the M371 uses 2G or 3G.
Choose the M371 for domestic lanes where 3G coverage is solid, and the M381 for cross border shipping or markets that have already retired their older networks.
How long can the M381 run on one shipment?
It depends on the upload interval and the battery. The standard 2000 mAh variants run around 30 days uploading hourly, or 50 days uploading every two hours. The XL variants with 4000 mAh reach roughly 60 and 100 days on the same intervals.
Tell us your transit time and we will confirm which variant and interval to specify.
What happens when the device passes through an area with no signal?
Readings continue to be taken and stored. When coverage returns, signal blind area data retransmission sends the backlog to the platform, so the record has no gaps. Data is also written to local flash memory in parallel, and can be exported as a PDF through the USB port regardless of what happened to connectivity.
How accurate is the positioning?
The M381 uses LBS positioning, which derives location from the mobile network rather than a satellite fix. It reliably identifies the city or route segment a shipment is on, which is the level of detail that matters when deciding where to intervene. It is not intended as a metre level GPS tracker.
How long is the data kept on the cloud platform?
Records are retained on the H7 platform for 3 to 5 years, covering real time data, over temperature alarm records, email and SMS alarm records and average records. That horizon matters because claims and audits often arrive long after a shipment has closed.
What is the minimum order quantity for the M381?
The minimum order quantity is 5 pieces, the same across our whole data logger range. That low threshold lets you run a real trial on one lane, watch the data arrive on the platform yourself, and confirm network coverage on your route before committing to volume.
OEM and ODM orders that require custom housing, private label printing or a customised cloud platform carry a higher minimum, since setup work is involved. Contact our sales team with your quantity and destination for pricing and lead time.
Other HLY data loggers
M371
3G Real Time Temperature and Humidity Data Logger
Same sensors, platform and housing as the M381, on a 2G and 3G module. The cost effective choice for domestic lanes with solid coverage.
M501
USB PDF Single Use Temperature and Humidity Data Logger
Armed with one button, 90 day recording cycle, IP67 housing and an encrypted PDF report at the destination.
M502-TH
USB Reusable Temperature and Humidity Data Logger
LCD display with live readings and alarm status, ±0.3°C accuracy, redeployable on closed loop routes.
Get M381 pricing for your lane
Send us your route, destination countries, required temperature range, transit duration and monthly volume. We will confirm network coverage on your lanes, the right variant and upload interval, unit price and lead time. The minimum order is only 5 pieces, so a trial run costs very little before you commit to volume.
- Manufacturer
- HLY TECHNOLOGY CO., LIMITED
- Office
- Baoan District, Shenzhen, Guangdong, China
- Phone
- +86 1331 8318 365
- sales@hly-logger.com