GE XMO2, Руководство пользователя

Страница: 32 / 196

Startup & Operation 3-1
September 2007
Introduction
This chapter provides instructions for starting up and operating the
XMO2 system. The following specific topics discussed:
•
powering up the XMO2 transmitter
•
establishing a sample gas flow
•
calibration of the analog output signal
If you have not already done so, please read Chapter 2, Installation ,
for details on mounting and wiring the XMO2 transmitter, the sample
system, and any other optional equipment.
Powering Up the XMO2
Transmitter
The XMO2 transmitter does not have a power switch. It begins taking
measurements and generating an analog output signal in the 0-25 mA
range as soon as it is connected to a 24 VDC power source. To power
up the system, simply energize the 24 VDC power supply.
Because the standard XMO2 measurement cell is controlled at a
constant 45°C (113°F) operating temperature, allow at least 30
minutes for the unit to warm up and reach temperature stability before
taking any measurements. During this time, you can establish a
sample gas flow through the system, as described in the next section.
Establishing a Sample
Gas Flow
Usually, the XMO2 transmitter is factory-calibrated at a sample gas
flow rate of 1.0 SCFH (500 cc/min) and at atmospheric pressure.
Unless otherwise specified on your XMO2 calibration sheet, optional
sample system tagging, or optional sample system instructions, your
XO2 should be operated at atmospheric pressure and at the flow rate
listed in Table 3-1 below.
Note:
For optimum performance, operating the XMO2 at conditions
other than those used for the factory calibration requires that
the unit be recalibrated at the actual field conditions.
Table 3-1: Recommended Sample Gas Flow Rates
XMO2 Type Flow Rate in SCFH (cc/min)
Weatherproof 1.0 ± 0.5 (500 ± 250)
Explosion-proof 1.0 ± 0.2 (500 ± 100)
Pressure-compensated 0.5 ± 0.5 (250 ± 50)