LEFOO LFM33 micro differential pressure transmitter/controller adopts high-precision MEMS digital pressure sensor, which can detect positive pressure, negative pressure or differential pressure products with optional analog signal 4~20mA & 0~10V or RS485 signal output; optional relay switch control, supporting a variety of working mode settings to match the actual application requirements; can independently set the relay switch action pressure point; through the internal The pressure unit can be switched and the digital damping filter can be edited on the spot, which is widely used in air or neutral gas detection and control. Suitable for all kinds of ventilation, air conditioning systems and equipment gas pressure detection, clean rooms, laboratories, gas pipeline filter resistance of differential pressure detection applications.
Features
* High precision MEMS digital pressure sensor to detect positive, negative or differential pressure
* Multifunctional product combining LCD digital display, switch control and transmitter output
* Adjustable internal range output range, multiple pressure units can be switched
* Built-in buzzer, provide sound and light glance, can set the alarm pressure value range on site
* RS-485 serial communication, support standard Modbus RTU protocol
* Flame-retardant ABS shell, with good impact resistance, heat resistance and other properties
Transmitter
| Technical Benchmark | ||
Measurement range | ±100Pa,±1000Pa,±10000Pa | |
Accuracy | ±1%F.S | |
Measured Medium | Air or non-corrosive gases | |
Storage Temperature | -20℃~70℃ | |
Protection Grade | IP65 | |
Output Signal | 4~20mA&0~10V | RS485 |
Control Signal | SP1 Relay Output | SP2 Relay Output |
Relay Type | 2 SPDT relays 3A@250VAC/30VDC | |
Power Supply | 16~30VDC | |
Consumption | ≤2.5W | |
Pressure Connection | Plastic Concave Interface | |
Housing Material | ABS Industrial plastic (UL94-V0) | |
Certification | ROHS, CE | |
Electromagnetic Compatibility | Electromagnetic transmit: EN50081-1/-2 Electromagnetic sensitivity: EN50082-2 | |
Display | 80*40mm LCD Display | |
Weight | 328g | |
| How to Select | |||||||||
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Code and Description | Remark | ||||||||
LFM33 | Model | ||||||||
6 | -100~100pa | Measurement range | |||||||
0 | -1000~1000Pa | ||||||||
2 | -10000~10000Pa | ||||||||
A | 4~20mA&0~10V | E | RS—485 | Output Mode | |||||
P | Plastic panel (round) | Installation panel | |||||||
S | Stainless steel panel (square) | ||||||||
F | Front panel air intake | Air intake method | |||||||
B | Rear panel air intake | ||||||||
LFM33 | 0 | A | P | B | Example | ||||
Connection Mode

■ Various switchable pressure units
■ Support multiple working modes
■ Built-in buzzer with sound-light alarm, the field-programmable alarm pressure value
■ RS-485 serial communication, support standard Modbus RTU protocol
■ Housing made of FR-ABS, satisfactory impact resistance and heat resistance etc.
■ The Max. and Min. pressure range of discrete output can be set
Various pressure units can be switched to view the lowest and highest pressure values. It also provides an acousto optic alarm and digital damping filtering degrees can be programmed on-site. The product adopts imported micro-pressure core body, digital pressure acquisition, and temperature compensation, with sensitive pressure response, long-term output stability, superior temperature performance, and other characteristics.
Air or neutral gas detection control
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