Heat flow meter is used to measure water heat supply in closed pipe. We mainly provide ultrasonic heat flow meter on the basis of our transit-time ultrasonic flow meter. In some areas, heat meter is also called as BTU meter that’s because BTU is one kind of energy measuring unit.Before ultrasonic heat meter released, mechanical heat meter is the main solution. But mechanical type has many disadvantages: short lift, poor accuracy, etc. Ultrasonic heat meter can solve the problem above.

Ultrasonic heat flow meter is mainly comprised of three parts: ultrasonic flow converter with heat function, ultrasonic flow sensor and temperature platinum resistors. The flow meter is used to test water flow rate and PT resistors are used to gather temperature difference between inlet and outlet of water flow. The platinum resistors can be PT100 (external power supply) and PT1000(battery power supply). They can be clamp on type or insertion type. Insertion type should be more accurate than clamp on type. Each set of PT100 or PT1000 contains 2pieces and the 2pcs should be calibrated.

Our energy calculating system is designed on the whole consideration. Many companies are still using the separated energy calculator. Our ultrasonic flow/heat meters provide Modbus and M-BUS protocol for network management.

In order to have an understanding to heat flow meter, we can borrow the classification from our ultrasonic flow meters as below:

Portable Clamp On Heat Flow Meter


Portable heat meter refers to battery powered portable ultrasonic flow meter with clamp on flow sensors and clamp on PT100 resistors. The configuration doesn’t need to cut pipe and provides mobile and convenient measurement of water flow and energy. It can be used for flow/energy check and survey.

Portable heat meters have two types: handheld type and portable type. Built-in mini printer or data logger are optional for data recording. User can select it as requirement. After fully recharging, the portable heat meter can work for 10-24 hours decided by different types. Longer battery can be made,but it will enlarge the size of flow converter.

For the technical specification, please refer to that of handheld&portable ultrasonic flow meters.

Fixed Clamp on Heat Meter

Fixed clamp on heat flow meter is used for exact size pipe for long-term, and it doesn’t need to move it often like portable type. It is usually powered by external power,mainly have 110-240Vac or 8-36Vdc or solar power. Both ultrasonic flow sensors and PT100 resistors are clamp on type and doesn’t need to cut pipe. So it inherits many advantages of clamp on flow meters. The flow/energy converter part can select wall mounted unit,desktop unit,low cost unit,etc.

Fixed Insertion Heat Flow Meter

Insertion ultrasonic flow sensors are suitable for pipe size over DN50mm. It is widely used for its stable performance and light-weight. It just requires to drill holes on pipe and doesn’t cause big damage to pipe. Meanwhile, for poor condition or cement pipe, it is an ideal choice where clamp on flow meter can’t work well. For insertion heat meter, it can be powered by battery or external AC&DC power. When battery power, use insertion PT1000 resistor. When external power, insertion PT100 is selected.

Fixed Inline Heat BTU Meter

Inline type is the most often used for flow meter or BTU meter. BTU meter usually refers to residential heat meter for home using. Its pipe size is usually DN15-DN25 and battery power. In the past,mechanical BTU meter is the main selection,but ultrasonic BTU meters are replacing it. Magnetic BTU meters have ever been an option,but it can’t compete with ultrasonic type. Thus, ultrasonic BTU meter has the promising prospect than others.

Except BTU meter,inline heat flow meter are also widely used for bigger pipe size. Though it requires to cut pipe largely,its installing is more convenience. And since historic reason, many existing BTU meters are inline structure,inline ultrasonic heat meters can make it quick to replace.

Inline Magnetic Heat Meter

We can also make magnetic heat meters as requirement. Equipped with PT100 resistor,electromagnetic flow meter can be functioned magnetic heat flow meter. Like fixed ultrasonic heat meter, it is usually external power and used for certain size pipe for long-term. It can provide higher accuracy,but better accuracy means higher cost. As the accuracy of our wetted ultrasonic flowmeter can reach 0.5 class, magnetic heat meter is not necessary solution. That’s why magnetic heat flow meter is not so popular like ultrasonic meter.


1).Energy Calculator. Some manufacturers can’t add energy calculating system to their flowmeters,thus they have to borrow separated energy calculator. This is not good choice.

2).Analog Temperature Sensor. Several companies who still use 4-20mA temperature sensor to gather temperature value. This is not recommended because 4-20mA is analog signal and  will reduce accuracy of temperature value. As a result,the accuracy of heat meter is degraded.

3).Modbus protocol. Modbus is  very popular industry communication protocol for network management. Several heat meters only use very rare register address for Modbus protocol. This is not real Modbus communication. You didn’t get what you have paid.

Typical Application-HVAC Energy Monitor&Management