Model 755R

Instruction Manual

748213-S April 2002

Needle

Model 755R

Valves

 

Oxygen Analyzer

 

 

Sample In

 

Two Micron

To Vent

 

Filter

 

Zero

Flowmeter

 

Standard

 

 

 

Gas

 

 

Span

Standard

Gas

Figure 2-1. Interconnect of Typical Gas Manifold to Model 755R

b.Pressure Requirements - General

Operating pressure limits are as follows: maximum, 10 psig (68.9 kPa); minimum, 5 psig vacuum (34.5 kPa vacuum).

CAUTION

RANGE LIMITATIONS

Operation outside the specified pressure limits may damage the detector, and will void the warranty.

The basic rule for pressure of sample and standard gases supplied to the inlet is to calibrate the analyzer at the same pressure that will be used during subsequent operation, and to maintain this pressure during operation. The arrangement required to obtain appropriate pressure control will depend on the application. When inputting sample or calibration gases, use the same pressure that will be used during subsequent operation. Refer to Section 2-3c (page 2-3), Normal Operation at Positive Gauge Pressures, or Section 2-3d (page 2-4) Operation at Negative Gauge Pressures.

c.Normal Operation at Positive Gauge Pressures

Normally, the sample is supplied to the analyzer inlet at a positive gauge pressure in the range of 0 to 10 psig (0 to 68.9 kPa).

CAUTION

HIGH PRESSURE GAS CYLINDERS

Pressure surges in excess of 10 psig during admission of sample or standard gases can damage the detector.

Maximum permissible operating pressure is 10 psig (68.9 kPa). To ensure against over-pressurization, insert a pressure relief valve into the sample inlet line. In ad- dition, a check valve should be placed in the vent line if the analyzer is connected to a manifold associated with a flare or other outlet that is not at atmospheric pressure. If the detector is over- pressurized, damage will result.

The analyzer exhaust port is commonly vented directly to the atmosphere. Any change in barometric pressure results in a

Rosemount Analytical Inc. A Division of Emerson Process Management

Installation

2-3