■ EDN.337, Pressure transmitter for refrigerant gas

- Applicable for NH₃ and HFC-134a

- No welding diaphragm (one-body structure)

- Designed for toxic gas environments

- Dedicated for refrigeration systems

- Accuracy ±0.5% F.S

- CE certified

 

■ Product Overview

In refrigeration systems using ammonia gas (NH₃) and refrigerant gas HFC-134a, the refrigerant gas HFC-134a is relatively stable; however, special care is required when used in industrial plants or confined spaces.

Due to the material characteristics, the flush diaphragm of the pressure sensor must be constructed as an integrated structure with the sensor body.

If the wetted parts are joined by laser welding or similar thermal welding methods, the chemical characteristics of toxic gases may cause the welded joint of the diaphragm to detach or separate.

The pressure sensor applied to EDN.337 has no welded joint. The flush diaphragm mounted on the upper part of the sensor body is a one-body integrated piezoresistive silicon pressure sensor.

Therefore, EDN.337 is an advanced pressure transmitter developed to prevent failures in conventional transmitters when exposed to ammonia gas (NH₃) and refrigerant gas HFC-134a (C₂H₂F₄).

■ Refrigerant Comparison

Category	R-134a (HFC-134a)	Ammonia (NH₃)
Chemical Formula	C₂H₂F₄	NH₃
Odor	Almost odorless (difficult to detect)	Pungent odor (easily detectable in case of leakage)
Toxicity	Very low (non-toxic)	Toxic (hazardous at high concentrations)
Flammability	Non-flammable	Slightly flammable (risk of explosion exists)
Environmental Impact	ODP(0), GWP (approx. 1300) → contributes to global warming	ODP(0), GWP(0) → environmentally friendly, but odor may be unpleasant
Operating Pressure	Medium	Relatively high
Refrigeration Efficiency (COP)	Standard (widely used in conventional refrigeration systems)	Very high (one of the most efficient refrigerants)
Material Compatibility	Compatible with most metals and rubber materials	Corrosive to copper → steel materials required
Applications	Automotive air conditioning, refrigerators, commercial refrigeration	Industrial refrigeration, large-scale cold storage, refrigeration plants
Cost / Maintenance	Low cost, easy maintenance	High initial cost, requires specialized operation
Typical Applications	Automotive AC, medium/small refrigeration systems, air conditioning	Food processing plants, cold storage, refrigeration systems, large-scale industrial refrigeration

 

■ Applications

▶ Automotive A/C and refrigeration systems

▶ Cold storage and food processing

▶ Industrial refrigeration systems

■ Accuracy Class

▶ ±0.5% F.S

■ General Specifications

Pressure range	-1…0 & -1…50 bar 0…1.6 to 0…40 bar
Accuracy	±0.5 % of F.S
Electrical connection	mPm plug DIN 43650 M12 plug 2m cable
Signal Output	4...20 mA, 2 wire-system 0…10V, 3 wire-system 0…5V, 3 wire-system 1…5 V, 3 wire-system
Wetted parts	No welding parts on diaphragm
Operating temperature	-20…+80 ℃ / standard -40…+125℃ / option