System-40 BTU Measurement System

The System-40 provides highly accurate thermal energy measurement in chilled water, hot water or condenser water systems. It is provided as a complete meter and includes a matched pair of platinum RTD temperature sensors and an integral inline ultrasonic flow sensor. It is available for use in ½” through 2½” piping systems with flow rates ranging from 0.03 to 250 GPM.


The native BACnet® MS/TP and MODBUS® RTU versions of the meter communicate energy, flow and temperature data directly to the network. Three auxiliary terminals can be configured at the factory to provide pulse outputs, inputs, a combination of the two, or even a single analog output.

Pulse outputs provide volume or energy totalization to the BMS.


Pulse inputs can bring in totalization pulses from local meters such as water, natural gas, or electric meters. Pulse input totals are accumulated in the internal registers and then transmitted to the RS-485 network. These totals are also available on the built-in display.


Analog output can be programmed to provide energy rate, volume rate, or temperature data to the BMS via a 4-20 mA / 0-10V / 0-5V signal.

Typical Applications

Chilled water, hot water and condenser water systems for:

  • Commercial office tenant billing
  • Residential apartment and condominium tenant billing

Reliable No-Moving-Parts Design

The System-40 utilizes direct path wetted ultrasonic transducers to measure flow. This no-moving-parts design optimizes signal strength and ensures long-term reliability.

Operates Over a Very Wide Flow Range

The built-in ultrasonic flow meter has a 500:1 turndown

Precision Matched Platinum RTD Temperature Sensors

1000 ohm sensors are matched to a differential uncertainty of better than ±0.18° F.

Auxiliary Pulse Inputs

The System-40 with BACnet® MS/TP or MODBUS® RTU can be ordered with three auxiliary pulse inputs for totalizing pulses from water, gas or electric meters. This simplifies network connectivity in the tenant space.

Simple Installation and Commissioning

Each meter is delivered fully programmed and ready for use upon delivery. Commissioning is done through the user interface/display without the need for special tools.

Detachable Calculator

The System-40 electronics enclosure is easily detached from the flow body to allow for remote wall mount installations using the 5’ cable provided with the meter.

C900.1 / EN1434 Compliant

The System-40 is designed to meet the requirements of C900.1 and EN1434

Catalog Sheets

Guide Specifications

Manuals