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  • 4 to 16 point sampling system using IR (NDIR) sensor technology, expandable to 48 points
  • Low detection limits (as low as 1 ppm)
  • Long sampling distances (up to 1,200 ft / 365 m)
  • On-board visual/audible alarms, 4 relay contacts mitigates refrigerant loss
  • Detects refrigerants (CFCs, HFCs, HCFCs, HFOs), ammonia, carbon dioxide
  • Measuring Range
    • Refrigerants: 0 to 10,000 ppm
    • Ammonia: 25 to 10,000 ppm
    • Carbon Dioxide: 300 to 8,000 ppm
  • Accuracy:
    • Refrigerants: up to ±1 ppm ±10% of reading
    • Ammonia: up to ±10 ppm ±10% of reading
    • CO2: up to ±5 ppm ±5% of reading
  • Modbus RTU via RS 485 digital output
  • Large Graphic LCD for easy set-up andreal-time monitoring
  • Powder-coated aluminum enclosure
  • Approvals: CE, UL, CSA, EN 61010-1, EN 61326, EN 14624

What's in the Box

  • Line end filters
  • End of line water stop filter assembly
  • Manual


The Bacharach HGM-MZ Multi-zone Gas Leak Monitor offers superior performance, flexibility and functionality for low level continuous monitoring of refrigerant gases used in most commercial systems including: Chlorofluorocarbons (CFC), Hydrochlorofluorocarbons (HCFC), Hydrofluorocarbons (HFC), Ammonia (NH3) and Carbon Dioxide (CO2). These state-of-the-art fixed gas monitors lead the industry in performance, integration capabilities, initial cost and cost of ownership. Capable of detecting more than 38 refrigerant gases, the Multi-Zone system is compliant with ASHRAE standard 15-2007, is ETL Energy Saving Listed, meets California Code Regulations for Refrigerant Monitors and is EN 14624 and CE certified.

The Multi-Zone is not only a leak detection system, but enables refrigerant management of e.g. a whole supermarket. The sooner a loss of refrigerant is detected, the earlier countermeasures can be initiated, resulting in smaller recharge quantities of refrigerants. With the on-board relays and the optional remote display, the Multi-Zone fulfills the regulatory requirements as a refrigerant detection system. Using the Modbus interface or analog output, the monitor can be integrated into any BMS/BAS system.

Bacharach HGM-MZ Multi-zone monitors provide continuous detection of refrigerant gas levels in up to 16 separate test zones and can be fitted with an optional two channel 4-20 mA current loop board for connection to remote monitoring equipment. Multi-Zone monitors retain a log of previous readings that can be easily accessed for analysis. Four relay contacts are provided that can be programmed to trigger external alarm devices in the event of a system fault, or if a leak (small), spill (medium) or evacuation (large) level of gas is detected, while audible and visual front panel indicators show alarm and fault conditions. With only minor periodic maintenance, such as the occasional replacement of filters, and active diagnostics that continuously check the system for proper operation, Multi-Zone monitors help maintain your equipment efficiency, promote safety and protect the environment.




Please consider these optional accessories.


This product can be used in the following applications:

Here's how some of our customers use this product...

Cold Storage Facility - Installation Considerations

Here are a few things to consider when installing the Bacharach HGM-MZ in a cold storage facility:

  1. The rule of thumb for sample points (pick up locations) is that each can cover a 20' radius. 2- and 3-way splitters are available to extend the range of any particular zone. From the splitter, the lengths must be equal.

  2. Refrigerants are heavier than air so sample points should 6 to 18" off the floor or in areas where refrigerant might collect. It is important to consider external doors and air currents inside the facility.

  3. When specifying, we need to know the method of communication. Is the communication 4-20mA, Modbus, or simply relay alarms? The Bacharach HGM-MZ uses 4-20mA to indicate the zone (ie: 4mA is zone 1, 5mA is zone 2, etc.) and then the level (scaled 4-20 mA output for the PPM detected).

  4. Heavily chlorinated HFC and CFC cleansers and explosive levels of propane will trip the sensor.

Identifying Refrigerant Leaks in Chilled Cases

The Background: Our customer is a supermarket chain that needs an effective way to monitor for refrigerant leaks from the chilled cases in their stores. Supermarkets have many of these chilled cases and risk food spoilage, increased operating costs, and EPA fines if the system leaks.

The Problem: Finding small leaks in a large space with many potential leaks points is a very difficult task complicated by the limited sensitivity of most leak detectors.

The Solution: The Bacharach HGM-MZ multizone gas leak monitor uses infrared sensing technology that is the most sensitive in the field, capable of detecting refrigerants levels as low as 1ppm. The HGM-MZ is a fixed location device that can monitor up to 16 zones providing excellent coverage over large areas and making the task of finding leaks much easier than before.