Source: Siemens 2023 | Author: Daniel Henningsen
To install legally billable measurements in the fields of heat, cooling, and chilled water measurements, these must be approved by a state-designated body and released for billable traffic (formerly calibration).
A distinction is made between a water meter (MI-001) or heat meter (MI-004) declared compliant according to Directive 2014/32/EU for measuring instruments (MID) or a cooling meter calibrated according to national law (PTB K7.2). Siemens also offers flow meters and energy calculators, each suitable, declared compliant, calibrated, and approved for the respective applications.
The table below compares these three approvals in terms of their definition, application area, and respective distinction, based on the respective standard sheets.
| Ml-001 Water Meter | Ml-004 Heat Meter | PTB K7.2 Cooling Meter | |
| Definition | A device designed to measure, store, and display the amount of water flowing through the sensor under operating conditions. | A heat meter is a measurement system designed to measure the heat delivered by a fluid used as a heat carrier in a heat exchanger circuit. Temperature differences: typically 20 to 50 K Temperature level: approximately 70°C |
A cooling meter is a device designed to measure the heat absorbed by a fluid used as a heat carrier in a cooling operation within a heat exchanger circuit. Temperature differences: typically 6 K Temperature level: approximately 10°C |
| Application Area | For applications requiring the billing of clean cold (0.1 – 30°C) or hot water (30° - 90°C). | Heat quantity measurement, for example in heating systems, combined heat and power plants, etc. | Cooling quantity measurement. Cold side measurement in heating systems, server cooling systems, etc. |
| Distinctions | For MI-001, the calibration specifies a ratio of minimum to maximum flow rate. The flow meter is approved only within this range and only these measurements may be used for billing. More information can be found in the first entry of the Process Automation Tip series. Click here to learn more. |
A heat meter can consist of one or more devices, and each component must be certified according to MI 004.
A heat meter consists of the following components: 1x Flow meter 1x Energy calculator 2x Temperature sensors NOTE: It is essential to specify whether the measurement is on the warm or cold side as density is temperature-dependent and affects the measurement result. Generally, the flow meter is installed on the cold side. |
A cooling meter can consist of one or more devices, and each component must be certified according to PTB K7.2.
A cooling meter consists of the following components: 1x Flow meter 1x Energy calculator 2x Temperature sensors NOTE: It is essential to specify whether the measurement is on the warm or cold side as density is temperature-dependent and affects the measurement result. Generally, the flow meter is installed on the warm side. |
