Differential pressure switches and transmitters

Accurate pressure measurement is very important that the HVAC system works. For this case, we are offering differential pressure relays and differential pressure transmitters that are used in the systems. Differential pressure switches are used to start and stop fans or pumps and monitor air filter status in ventilation units or air handling units. Also, they protect duct electrical heaters from overheating. Differential pressure transmitters could be used for air filter monitoring, airflow measurement or staircase pressurization system. VAV boxes use a differential pressure sensor to measure and control airflow thereby regulating the room temperature. Pressure transmitters have a different range of pressure measurements. It is recommended to choose the measurement range as close as possible to your system. Then the accuracy will be significantly better.

Differential pressure switches

Differential pressure transmitters

Differential pressure switches

Differential pressure switches series 911.82 are used to start and stop fans or pumps and monitor air filter status in ventilation units or air handling units. In some cases, they are used in air handling units with heat exchangers to protect them from anti-frost. Also, they protect duct electrical heaters from overheating. They are delivered with two nozzles and 2 meter long plastic tube. It is possible to set lower differential pressure with a knob under the cover.

Features

Maximum operating range 10 000 Pa
Pressure connections 2 plastic pipe connection pieces (P1 and P2), external diameter 6.0 mm:

P1 for connection to higher pressure (marked +)

P2 for connection to lower pressure (marked –)

Contacts rating resistive load 1,0 A or inductive load 0,4 / 250 VAC
Ambient temperature from -20°C to +85°C
Protection class IP54

Instruction

Button

Product code	Pressure range
911.82 - 200	20 – 200 Pa
911.82 - 300	30 – 300 Pa
911.82 - 500	50 -500 Pa
911.82 - 1500	200 – 1000 Pa
911.82 - 2500	500 – 2500 Pa

Differential pressure transmitters

Differential pressure transmitters could be used for air filter monitoring, airflow measurement, or for staircase pressurization systems. VAV boxes use a differential pressure sensor to measure and control airflow thereby regulating the room temperature. Pressure transmitters have a different range of pressure measurements. It is recommended to choose the measurement range as close as possible to your system. Then the accuracy will be significantly better. We offer a pressure transmitter with output 0 – 10 V, with a possible LCD and Modbus communication via RS485.

Differential pressure transmitters 0-2500 PA

Differential pressure transmitters with LDC

Differential pressure transmitters with modbus

Differential pressure transmitters 0-2500 PA

This series of air differential pressure transmitters are used to measure differential pressure, overpressure and vacuum. They provide one adjustable pressure range and one output signal 0-10 V. It could be used for different applications such as building automation, air conditioning systems and clean room monitoring, filters and fans monitoring. The output signal can be calibrated to zero by pressing the push button. The response time of the output signal can be configured using a jumper. If the application requires a fast response time, the jumper must be removed. 982R series differential pressure transmitter can be reset to its factory settings just by pressing the push-button for >10 sec.

Features

Power supply 18 - 30 VAC / VDC
Output 0 – 10 VDC
Load for output ≥ 1kΩ
Working and storage temperature -20 + 70°C
6 mm hose connection
Protection class IP54

Instruction

Button

Product code	Pressure range	Overload capacity
982R -100	0 – 100 Pa	60 kPa
982R - 250	0 – 250 Pa	60 kPa
982R -500	0 – 500 Pa	75 kPa
982R - 1000	0 – 1000 Pa	75 kPa
982R - 2500	0 – 2500 Pa	85 kPa

Differential pressure transmitters with LDC

The air differential pressure transmitters of the 984M series are used to measure differential pressure, overpressure and vacuum. They are eight different products by differential pressure range. This series of differential pressure transmitters have two output signals of 0 – 10 V or 4 – 20 mA, which could be changed by removing the jumper. The response time of the output signal can be configured using a jumper. If the application requires a fast response time, the jumper must be removed. The output signal of the 984M series differential pressure transmitters can be calibrated to zero by pressing the M push-button in the transmitter.

Features

Power supply 18 - 30 VAC / VDC
Output 0 – 10 VDC / 4 – 20 mA
Load for output 20 ... 500 Ω when output 4 – 20 mA
Load for output ≥ 1kΩ when output 0 – 10 VDC
Working and storage temperature -20 + 70°C
6 mm hose connection
Protection class IP54

Instruction

Button

Product code	Pressure range 1	Pressure range 2	Overload capacity
984M - 50	-50 – 0 Pa	0 – 50 Pa	60 kPa
984M - 100	-100 - 0 Pa	0 – 100 Pa	60 kPa
984M - 250	0 – 100 Pa	0 – 250 Pa	60 kPa
984M - 500	0 – 250 Pa	0 – 500 Pa	60 kPa
984M - 1000	0 – 500 Pa	0 – 1000 Pa	75 kPa
984M - 2500	0 – 1000 Pa	0 – 2500 Pa	85 kPa

Differential pressure transmitters with modbus

The transmitters of the series 985M are used to measure differential pressure and the 985V series - for volume flow or flow velocity and pressure. This kind of pressure transmitter could be used in different applications such as in building automation and air conditioning systems, overpressure measurement in clean rooms and laboratories and measurement of constant pressure in VAV applications. The response time of the output signal can be variably set via Modbus. LED display shows the pressure value, volume flow or flow velocity. If you want to calibrate the transmitter for 985M and 985V - press the MODE/Offset button or set it via Modbus in an unpressurized state to adjust the offset to zero.

Features