Differential pressure gauge YEJ

dialpanel-mountcapsule

Overview
The YEJ series rectangular capsule pressure gauge is designed specifically for accurate measurement of micro‑pressure and negative pressure in neutral, non‑explosive gases that do not corrode copper alloys. The capsule sensing element (two welded corrugated metal diaphragms) provides high sensitivity to pressure changes down to kilopascal or pascal levels. The distinctive rectangular housing fits neatly into industrial control cabinets and reduces zero‑point drift under vibration.

Two models for different needs

• YEJ‑101: High‑precision indication terminal for on‑site micro‑pressure monitoring. Ideal for boiler air supply and flue gas duct pressure measurement where no electrical output is required.
• YEJ‑121: Electric contact version that adds binary control outputs. Pre‑set upper and lower limits allow it to directly drive relays, alarms, or PLC inputs for automated control or limit‑based alarming.

Key Features

• Exceptional low‑pressure sensitivity — the capsule element expands proportionally to incoming pressure, driving a gear transmission mechanism that moves the pointer smoothly across the scale for accurate, repeatable readings at very low ranges.
• Rectangular housing design — easier to mount in narrow spaces or panel cutouts compared to circular gauges; rectangular shape offers internal space for electric contact mechanisms when equipped.
• Low air intake/exhaust — the gauge consumes very little air during measurement, so it does not disturb the pressure of the system being measured.
• Contact output (YEJ‑121) — preset pressure upper/lower limits trigger relay or PLC inputs, enabling automated safety interlocking or alarm functions without an external controller.
• Simple mechanical reliability — no external power needed for the YEJ‑101 indicator; provides reliable first‑hand pressure data even during power fluctuations.

Basic Specifications (At a Glance)

• Series: YEJ series
• Models: YEJ‑101 (indicator), YEJ‑121 (electric contact)
• Accuracy class: 2.5
• Weight: YEJ‑101: 2 kg; YEJ‑121: 2.5 kg
• Pressure connection: φ8 (fits φ6 inner diameter hose)
• Ambient temperature range: –20°C to +60°C
• Relative humidity: ≤85% RH
• Measurement ranges: positive, vacuum and compound ranges from Pa‑level up to tens of kPa (0 ~ 250 Pa … 0 ~ 60,000 Pa; –250 ~ 0 Pa … –60,000 ~ 0 Pa; –120 ~ +120 Pa … –30,000 ~ +30,000 Pa)

Electrical data (YEJ‑121 only)

• Setting error: < 2.5% of full scale
• Contact capacity: 3A 220V AC (non‑inductive load)
• Power supply: AC 220V
• Power consumption: < 5W

Measurement Ranges

• Positive pressure: 0 ~ 250 Pa up to 0 ~ 60,000 Pa
• Vacuum: –250 ~ 0 Pa up to –60,000 ~ 0 Pa
• Compound (pressure/vacuum): –120 ~ +120 Pa up to –30,000 ~ +30,000 Pa

Applications

• Boiler ventilation systems and combustion air monitoring
• Flue gas duct pressure measurement
• Dust collection systems
• Cleanroom pressure differential monitoring
• HVAC air pressure control
• Laboratory and environmental test stands
• Non‑corrosive, neutral gas pressure indication

Installation & Model Selection
Both YEJ‑101 and YEJ‑121 are designed for direct pipeline connection using the supplied φ8 pressure port (compatible with φ6 inner diameter hoses). Choose the YEJ‑101 when only on‑site pressure indication is required without electrical output. Choose the YEJ‑121 when automated control or alarming based on pre‑set upper and lower pressure limits is needed; internal contacts will switch at desired thresholds to directly operate relays, buzzers, or feed signals to a PLC.

YEJ Series
The YEJ series is designed for low‑pressure measurement and straightforward installation.

Technical specifications

• Series: YEJ series
• Models: YEJ‑101 (indicator), YEJ‑121 (electric contact)
• Accuracy class: 2.5
• Weight: YEJ‑101: 2 kg; YEJ‑121: 2.5 kg
• Pressure connection: φ8 (fits φ6 inner diameter hose)
• Ambient temperature range: –20°C to +60°C
• Relative humidity: ≤85% RH
• Measurement ranges: positive, vacuum and compound ranges from Pa‑level up to tens of kPa (0 ~ 250 Pa … 0 ~ 60,000 Pa; –250 ~ 0 Pa … –60,000 ~ 0 Pa; –120 ~ +120 Pa … –30,000 ~ +30,000 Pa)
• YEJ‑121 electrical: setting error < 2.5% FS; contact capacity 3A @ 220V AC (non‑inductive); power supply AC 220V; power consumption < 5W
• Sensing element: rectangular capsule (two welded corrugated metal diaphragms)
• Housing: rectangular case for panel mounting and improved vibration resistance