Our low cost NetGuards are our lastest Temperature Guard offering.


They are designed to simply and easily monitor a refrigerator/freezer storing temperature sensitive drugs and samples at a very competitive price.

Absolutely no ongoing fees!

Designed to Meet All VFC Requirements

  • Monitor two temperatures from -328°F to 392°F

  • Optional built-in ambient temperature and humidity sensor

  • Calibrated measuring range: -148°F to 78°F with +- 1°F accuracy

  • Wifi version is available
  • Available with A2LA or NIST certificate

  • Displays current, Min, Max temperature readings

  • Internal alarm buzzer (85dB) actively notifies out-of-range temperatures

  • Low battery indicator

  • 4000 readings memory storage

  • User programmable logging interval

  • Comes with free software to download log file, send alarm emails/text messages.

M308 Ethernet NetGuard

Feel free to call us if you need more information or to order

M308: $345

M308 with NIST calibration certificate: $375

Add an internal ambient temperature and

humidity sensor to the M308: $45


Apps available for Android and iOS



The M308 can monitor two temperature sensors and two door inputs, which is perfect for a fridge/freezer combo unit.

Runs for up to six hours without power on its internal rechargeable batteries, continuously logging data in its internal memory.

Stores up to five months worth of data on the M308's internal memory.

Stores 180 days of daily Hi-Lo temperature data for each sensor.


Download the temperature log file via our free Data Capture software.


Our free PC based Data Capture software simplifies your temperature recording tasks by automatically recording the temperature status of all of your M308 units across your entire network. Data Capture also sends out alarm emails and text messages when a sensor goes out of limits.


  • Onboard storage records 4000 temperature readings

  • 180 days of daily Hi-Lo temperature readings for each sensor

  • Local audible alarm

  • Relay output for connecting to an existing security system or strobe

  • Programmable high and low limits for each sensor

  • Programmable alarm time delay for each refrigerator/freezer

  • Data Logging capabilities


  • Maximum temperature sensor range: -328°F to 392°F, -200°C to 200°C

  • Factory calibrated range -148°F to 78°F (-100°C to 21°C) to better than 1°F degree

  • Field calibration can be performed at one point

  • Measurement resolution 0.1°

  • Sensor Type: 1000 Ohm Platinum (.00385 TCR)

  • Number of Temperature Inputs: 2

  • Number of Door Sensor Inputs: 2

  • Internal Memory:  4000 records

  • Internal Memory Data Update Rate: Programmable 1 to 60 minutes

  • Internal alarm buzzer

  • Rechargeable battery backup included keeps the M308 operating for up to 2 days (except for network connection).

  • Internationally compatible plug-in wall transformer included (100-240v 50-60hz) Standard US plug.

  • Operating Temperature Range 32°F to 125°F

  • Enclosure Dimensions: 5.625" x 3.250" x 1.375"


Microtechnologies, Inc.
Farmington, CT 06032

Sales & Support

© 2019 By Temperature Guard