PRODUCTS

Intended Use & Applications

• Primary function: Measurement of low positive pressure, negative pressure (vacuum), and differential pressure of non-corrosive gases.

• Secondary function: Calibration of other pressure instruments (when used with a regulator).

• Typical users:

  • University teaching and research laboratories

  • Metrology and calibration institutions

  • Coal mining enterprise laboratories

  • Industrial HVAC and ventilation testing

  • Filter resistance measurement

  • Cleanroom pressure differential monitoring

---

Key Features

• High accuracy for micro-pressure measurements

• Compensated design eliminates liquid level reading errors

• Clear scale plate with mmH₂O graduations

• Smooth adjustment mechanism for precise pressure setting

• Built-in leveling system for accurate vertical alignment

• Attractive, durable housing suitable for laboratory environments

---

Technical Specifications

Note: Please refer to the product nameplate or contact Xi’an Yunyi for the exact range and accuracy of your specific model, as the original webpage did not list numerical values.

---

Construction & Components

The Compensated Micro-manometer consists of four main sections: the fine adjustment part, the level observation part, the reflector part, and the housing part.

1. Fine Adjustment Part

• A fine adjustment dial engraved with 200 equal divisions is fixed onto a long lead screw.

• The lead screw drives the water storage cylinder up or down.

• An indicator slider is attached to the static pressure connection nozzle on the water chamber.

• The slider moves along a graduated scale, indicating the displacement height of the water storage cylinder.

2. Level Observation Part

• A level head is installed inside the observation tube.

• The operator observes the change in liquid level inside the observation tube when pressure is applied through the dynamic pressure tube.

3. Reflector Part

• A reflector mirror is fixed within the mirror housing.

• The mirror reflects the contact condition between the level head inside the observation tube and the liquid surface.

• Zero adjustment (“base point”): The operator adjusts until the tip of the level head touches its own reflected image (the two tips meet). This indicates the correct “base point” reference for taking readings.

4. Housing Part

• The housing and cross-arm support the long lead screw.

• A leveling bubble (spirit level) and leveling screws are mounted on the housing.

• These allow the operator to adjust the vertical alignment of the lead screw and the dynamic pressure tube before use.

---

Operating Principle (Simplified)

The compensated micro-manometer works on the principle of balancing an applied pressure against the hydrostatic pressure of a liquid column (typically water or a low-viscosity oil). By adjusting the water cylinder height using the fine adjustment dial, the operator brings the liquid level back to a fixed reference point (observed via the reflector). The applied pressure is then read directly from the scale and dial, compensated for any zero drift – hence the name “compensated.”

---

Included in Standard Delivery

• Compensated Micro-manometer main unit

• Leveling bubble (spirit level) – pre-installed

• Adjustment tools

• Operating manual (Chinese / English available upon request)

Not included (required for operation):

• Working liquid (distilled water or specified fluid)

• Connecting hoses

• Pressure regulator (if used for calibration)

• External pressure source (if required)

---

Operation & Safety Notes

Before Use:

1. Place the instrument on a stable, vibration-free horizontal table.

2. Adjust the leveling screws until the leveling bubble is centered.

3. Fill with the specified working liquid to the correct level (see manual).

4. Perform the “base point” zero adjustment using the reflector and fine adjustment dial.

During Use:

• Ensure the gas being measured is non-corrosive to prevent damage to internal components.

• Do not exceed the maximum rated pressure range.

• Make all connections carefully to avoid leaks.

• Allow sufficient stabilization time after each pressure change.

After Use:

• Release all pressure before disconnecting.

• Clean any spilled liquid immediately.

• Cover the instrument when not in use to prevent dust contamination.

General Care:

• Re-calibrate periodically according to local metrology regulations.

• Handle the glass observation tube and reflector with care.

• Store in a clean, dry environment within the specified temperature range.

---

Ordering Information

To order the Compensated Micro-manometer, please specify:

• Required pressure range (mmH₂O)

• Required accuracy class

• Preferred working liquid (if other than water)

• Any calibration certificate requirements (standard or traceable)