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Temperature Guard has been making quality products since 1977. We currently specialize in Food Service, Medical, and Industrial grade applications. We offer quality products from a family business.

Wireless NetGuard - M307 Designed to Meet VFC Requirements


M307 Bottom

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

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

Built in room temperature and humdity sensor

Available with A2LA or NIST certificate

Displays current, Min, Max temperature readings

Alarm 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

Order Now $345

Order with NIST Certificate add $30
Order with A2LA Certificate add $100


  • Description
  • Features
  • FAQ
  • Specifications
  • Sensors
  • Documents


The M307 operates on your wireless Ethernet network to monitor two temperature zones, two door inputs, perfect for a fridge/freezer combo unit.

The M307 runs for up to 6 hours without power on its internal rechargeable batteries, continuously logging data in its internal memory.

Store up to a 5 months worth of data on the M307's internal memory.

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 M307 units across your entire network. Data Capture also sends out alarm emails and text messages when a sensor goes out of limits.



  • Built-in 802.11 b/g/n
  • Onboard 4000 reading data storage
  • Local audible alarm
  • Solid state relay output for connection to existing security system
  • Programmable high and low temperature limits for each sensor
  • Programmable alarm time delay for each refrigerator/freezer
  • Data Logging Capabilities


IEEE 802.11i - PSK with AES-CCMP Encryption
TKIP Encryption
64/128-bit WEP


How does the M307 work?

The M307 is designed to monitor two temperature zones such as a refrigerator and freezer or any two zones you like.

Step 1: Get the M307 on your wireless Ethernet

Step 2: Connect the temperature sensors

Step 3: Download and install our free Data Capture software which is required to program the M307 and collect the temperature data

When a sensor goes out of limits, the M307 will sound it's alarm and Data Capture will send out alarm emails and or text messages.  Data Capture has to be running on a PC for the emails to be sent.  The alarm can be canceled with a push of a button.

The M307 maintains a temperature log file of up to 5 months worth of data.  This data can be downloaded with a our free Data Capture software.


  • 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
  • Network Interface: 802.11 b/g/n
  • Internal alarm buzzer
  • Rechargeable battery backup included keeps the M307 operating for up to 2 days.
  • 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"


You can connect two external temperature sensors to the M307 which is perfect for monitoring a combo refrigerator/freezer or any two zones.

Available sensors can be seen here Sensors and Accessories . For simple installation we recommend the BP2-G Flex Kit. The kit includes a temperature sensor in a vial filled with glycol and a flex kit that makes installation a snap.

The M307 has an optional, built-in temperature and humidity sensor, to monitor ambient conditions.

Sensors that you can use with the M307:

  • LTS-V for Ultra-low temperatures
  • BP2-G, BP-V for temperatures between -58°F to 328°F
  • R for room temperature
  • SP Stainless Plate temperature sensor for walk-in fridges/freezers
  • DR Door input sensor to monitor for doors left open
  • WTR Water Sensor for monitoring water leaks




Getting Started

Wireless Setup Manual How to get the M307 on your wireless network.

Wiring Diagram