Neptune Systems Conductivity Temperature Probe Module

Probe
Temperature
Keeping a stable and consistent temperature in the aquarium is paramount to the health of your inhabitants. Monitoring temperature and especially temperature changes throughout the day is mission critical.

Having a quality temperature monitoring solution that also alerts you to over or under temperature situations is a must for a successful aquarium.

Compatible with:
Any available temperature port on the following products: PM1, PM2, PM3, ASM & A1, A2, or A3 Apex Series

Included with Apex Jr, Apex, Apex Pro

The Neptune Systems Conductivity Temperature Probe Module, commonly known as the PM2 module, is a crucial component for any serious reef aquarist using a Neptune Systems Apex controller. It allows for precise, real-time monitoring of two extremely important water parameters: salinity (conductivity) and temperature.

Here's a detailed look at its features and how it functions:

Key Features and Functions of the PM2 Module:

1.  Conductivity/Salinity Monitoring:
Core Function: The primary purpose of the PM2 is to connect a conductivity probe (sold separately) to your Apex system. This probe measures the electrical conductivity of the water, which is directly related to its salinity.
Real-time Data: It provides continuous, real-time readings of your tank's salinity, displayed on your Apex Fusion dashboard.
Measurement Ranges: The PM2 typically supports multiple measurement ranges (e.g., 0-900 µS/cm, 0-90.0 mS/cm, 0-50 ppt) to cater to various aquarium types (freshwater, brackish, marine).
Alerts and Automation: You can set up custom alerts (email, SMS) if salinity deviates from your desired range. More importantly, you can program the Apex to trigger automated responses, such as shutting off pumps or sending notifications, to prevent catastrophic issues.
Temperature Compensation: This is a critical feature. Salinity readings are highly sensitive to temperature. The PM2, when connected to a temperature probe (also connected to the PM2), uses the real-time temperature data to automatically compensate the conductivity reading, providing a much more accurate and consistent salinity value. This is why having both probes connected to the same PM2 module is essential for precise measurements.
Galvanic Isolation: The PM2 incorporates galvanic isolation, which helps prevent electrical interference and ground loops. This is vital for obtaining accurate and reliable probe readings in an electrically complex aquarium environment.

2.  Temperature Monitoring:
Dedicated Port: The PM2 includes an additional temperature probe port. While your main Apex unit usually has a temperature probe, having an extra one on the PM2 allows for dedicated temperature compensation for the salinity probe, or for monitoring temperature in a different section of your system (e.g., a refugium, frag tank).

3.  Digital Input/I/O Expansion:
Six Digital Inputs: Beyond conductivity and temperature, the PM2 features six digital inputs. These are incredibly versatile and can be used to connect various "dry contact" switches, such as:
Float switches: For auto top-off (ATO) systems, sump level monitoring, or controlling reservoir levels.
Leak detection probes: To trigger alarms or shut-off equipment if water is detected outside the tank.
Pressure sensors: For monitoring filter pressure or other systems.
Push buttons: For manual overrides or feeding modes.
Requires Breakout Box: To connect these digital inputs, you typically need a Neptune Systems Breakout Box, which plugs into the I/O port on the PM2 (or the Apex main module).

4.  Integration with Apex System:
AquaBus Connection: The PM2 connects to your Apex controller via an AquaBus cable, becoming part of your Apex network.
Plug-and-Play: It's designed for easy plug-and-play setup. Once connected, your Apex controller automatically recognizes the module.
Datalogging and Graphing: All data from the connected probes (salinity, temperature, and I/O states) is logged and graphed within Apex Fusion, allowing you to track trends and review historical data.
Upgradeable Firmware: The PM2's firmware can be updated through the Apex system, ensuring compatibility with new features and improvements.

How it Works (Simplified):

1.  Conductivity Probe: The conductivity probe, submerged in your aquarium water, applies a small electrical current and measures how easily that current passes through the water. Water with more dissolved salts (higher salinity) conducts electricity more readily.
2.  Temperature Probe: The temperature probe simultaneously measures the water's temperature.
3.  PM2 Processing: The PM2 module receives the raw conductivity and temperature readings.
4.  Temperature Compensation:Using the temperature data, the PM2 adjusts the conductivity reading to a standard reference temperature (typically 25 Celsius). This compensates for the fact that conductivity naturally increases with temperature, ensuring that your reported salinity is accurate regardless of small temperature fluctuations in your tank.
5.  Data Transmission to Apex: The compensated salinity (and raw temperature) data is then sent to your main Apex controller via the AquaBus.
6.  Apex Fusion Display & Automation: The Apex controller processes this data, displays it in Apex Fusion, and executes any programmed rules or alerts based on your configured salinity and temperature parameters.

Compatibility:

The PM2 module is compatible with all Neptune Systems Apex controller models, including the Apex (2016), Apex Classic, Apex Lite, Apex Jr., and the A1, A2, and A3 Series Apex (A3 Jr, A3 Apex, A3 Pro).