Mobeye ThermoGuard TwinLog CML4255 Temperature Alarm

Brand: Mobeye

 375,00 ( 309,92 excl. VAT)

In stock.

The Mobeye ThermoGuard TwinLog CML4255 is a comprehensive and user-friendly temperature monitor equipped with alarm and logging functions, ensuring dependable ambient temperature monitoring. It features a built-in communication module capable of connecting to both the 4G LTE-M and 2G networks.

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Communication module

4G LTE-M, 2G Fallback


2x digital temperature input, 2x NO/NC inputs


1x open collector (200mA)

Temperature range

-10 to +50 degrees Celsius (ambient temperature), -35 to +70 degrees Celsius (sensor)

Power input

battery-operated (with option to connect 12VDC power source)


2x CR123 (lithium 3,0V) included


94 x 94 x 28 mm

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Mobeye ThermoGuard TwinLog CML4255 Temperature Alarm

The Mobeye ThermoGuard TwinLog CML4255 is an extremely precise and user-friendly temperature monitor. Whenever the temperature deviates from the preset limit values, you will receive an alarm notification. Additionally, it records temperature values at user-defined intervals and presents them on the online portal.

The CML4255 features a dependable temperature sensor, with an optional second sensor. The device can be powered by batteries or an external power source. The built-in communication module can connect to both the 4G LTE-M and 2G networks.

Automated Temperature Monitoring

CML4255 in Mobeye Internet Portal
Mobeye Web App

The CML4255 measures, monitors, and logs temperature values. If the temperature or any of the inputs indicate an alarm status, the CML4255 notifies you through the app (available for iOS/Android), telephone calls (voice messages), text messages, and/or emails. You can configure the contact persons with various options for the alarm messages.

The logging functionality is accessible when using the Mobeye Internet Portal. The recorded temperature values are periodically transmitted to the portal and after an alarm for display in table and graph formats.

The Mobeye ThermoGuard TwinLog CML4255 can operate for over a year on a single set of batteries. When using an external power source (12-24V DC or mains), it also sends notifications for power failures.

Temperature Sensor

The temperature sensor is digital and highly accurate. The adjustable minimum and maximum temperature limits range from -35°C to +70°C. The sensor comes factory-calibrated and displays values in decimals. You can customize the interval for logging and transferring the values to the portal.

The standard product includes one sensor, and you can optionally connect a second sensor.

Alarm Messages

In the event of an alarm, the Mobeye ThermoGuard TwinLog sends alarm notifications via the app (iOS/Android), telephone call (voice message), text message, and/or email. The message includes the current temperature.

For push messages, you have the option to choose between an escalation plan or a group message. The escalation plan allows the recipient to acknowledge the push message, preventing other contacts from receiving it. If none of the recipients acknowledges the push message, a phone call is initiated. There is no limit to the number of contacts.

CML4255: External Voltage vs Battery Powered

The ThermoGuard TwinLog CML4255 is a wireless temperature monitor and logger. It can run on batteries for an extended period, making it independent of an external power source. However, if an external power source is available, it is recommended to connect it. Then, the power supply’s availability is continuously monitored, and it will also send power failure alarms. In the event of a malfunction, a notification will be sent, and the batteries take over, allowing the CML4255 to continue monitoring and sending alarm messages. Another notification will be sent once power is restored.

Batteries are included. A country-specific mains adapter is available as an accessory.

Alarm Inputs, Piezo Siren, and Open Collector Output

In addition to the temperature sensor, the Mobeye ThermoGuard TwinLog CML4255 features two NO/NC inputs for connecting alarm contacts and sensors. These inputs can be used to monitor the status of a make/break sensor or device, such as an air conditioner or door magnet. In the event of an alarm, the internal piezo siren can produce an audible local alarm. Additionally, there is an open collector output for switching an external device.

How it Works

Mobeye CML4255 how it worksThe Mobeye CML4255 continuously measures temperature values and periodically logs them. This ensures that you are fully informed about alarm situations and can track the complete temperature trend.

  1. When placing the sensor, select a location with a stable temperature and avoid positioning it too close to heat sinks or heat sources.
  2. Set the temperature limits and log frequency and choose the contacts for notifications.
  3. If it gets too cold or too hot, the ThermoGuard TwinLog sends alarm messages to the contacts. The logged values can be viewed online in table and graph form.

Typical Applications for the Mobeye ThermoGuard Twinlog CML4255

The Mobeye CML4255 is a wireless temperature logger. The instant alarm, periodic logging and remote insight make the CML4255 suitable for professional applications such as

  • Food chains
  • Conditioned storage
  • Medical fridges and freezers
  • Cold storage
  • Powder storage, to prevent explosions
  • Dyeing and drying
  • ICT server rooms
  • Animal shelters

For utilisation in wet or damp areas, outdoor environments, or industrial settings, opt for the Mobeye CML4275.


CML4255 – Technical data


  • CML4255
  • 1x digital temperature sensor
  • 2x CR123 batteries
  • SIM card

(Alarm) messages

  • temperature alarm, input alarm, power failure, alarm recovery, battery low voltage, (missed) test report
  • to private contacts via app, call, text message and/or e-mail
  • local piezo siren


  • temperature value
  • status
  • setting list
  • event history
  • network strength
  • position based on Cell ID

Setting options

  • temperature limits per sensor (between -35 °C and +70 °C)
  • log interval (in min.)
  • interval for data synchronisation (in hours)
  • contact persons (unlimited number) for alarm and service messages
  • message texts
  • repeat cycles
  • input type
  • recovery messages
  • alarm delay times
  • test interval (keep-alive)
  • etc.


  • arming and disarming via button, time schedules and SMS

Temperature sensor

  • 1 meter cable
  • accuracy: 0.5°C between -30 °C and +55 °C, 1 °C outside these limits


  • 2x digital temperature input
  • 2x NO/NC input (potential-free)
  • 1x 12-24V DC (+/- 2V)


  • open collector (at external voltage), max. 200mA. Switches in the event of an alarm or after incoming SMS/call

Power supply

  • 2x CR123 lithium batteries or 12-24V DC (regulated) + 2x CR123 lithium

Battery lifetime

  •  > 1 year at normal use (battery operated)
  • > 3 years at normal use (powered externally)


  • 94 x 94 x 28 mm


  • 4G LTE-M (worldwide) + 2G EGSM Quad band

The Mobeye SIM card and Internet Portal provide full functionality and optimum security. The 4G LTE-M network is very reliable and ensures a strong penetration against low energy consumption. 2G is available as a fallback.

  • 2G EGSM Quad band (850/900/1800/1900 MHz)

When using your own SIM card, the device works (only) on 2G. The operation is “stand-alone”, without using the Mobeye Portal and without the log function. The alarm notifications are sent via SMS and telephone call to (max.) 5 contacts. Programming is done via (simple) SMS commands.

Accessories (not included)

  • 2nd temperature sensor (1m or 10m cable)
  • extension cable (3m, 10m or flat 1m cable)
  • mains adapter
  • external antenna

Mobeye SIM, Portal & App service

The Mobeye Internet Portal offers a clear dashboard and essential functions, such as graphs and log values, history, status and position (Cell-Id), online programming, setting up the messages and push notifications per app. The ‘keep–alive’ monitor offers extra security by monitoring the receipt of test messages. You can activate the supplied Mobeye SIM card online.


Click to open the documents and find more information:

SIM, Portal & App

All Mobeye monitoring devices require a SIM card for communication. The product comes with a budget-friendly SIM card, which provides direct access to the Mobeye Internet portal. Alternatively, you have the flexibility of using your own SIM card.

The Mobeye M2M SIM card provides the device with full functionality, allowing access to the Mobeye Internet Portal and App.

With the Mobeye SIM card, communication occurs over the 4G LTE-M network with 2G as a fallback. When you insert your own SIM card, the device utilises the 2G network. Alarm messages are then transmitted via SMS and/or call to a maximum of 5 telephone numbers.

The Mobeye SIM card is PIN-protected and exclusively functions in a Mobeye device. Please refrain from inserting it into another device. For further information about the Mobeye SIM card, visit: The rate for utilising the Mobeye Internet Portal and the SIM card can be found at

Free App for your Smartphone
The Mobeye Messages app is available for download from the Google Play (Android) and Apple App Stores (iOS).

Would you like to use the Mobeye SIM card, but it was not included in your package? Please contact the MobeyeStore team to request one by completing the contact form.


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