Ametek Thermox CEM O2/TM, User Manual

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5-2 | Thermox CEM O2/TM
Definitions
Calibration vs. Verification Operations
The Series 2000 control unit software refers to both calibration and verifi-
cation operations. During a verify operation, a calibration gas reading is
taken, and the difference between what the system records for the gas
value and its known value (from the gas cylinder) is recorded. Internal
calibration parameters are not changed. Verify operations are often used
to check that the instrument is running within required tolerances. During
a calibration operation, software algorithms adjust the difference between
the current readings and the known calibration gas values until they are
equal.
Span vs. Zero Gas
This chapter also refers to the terms span and zero calibration gases. The
span gas is the high calibration gas. The zero gas is the low calibration gas.
Types of Calibrations
The Series 2000 control unit allows you to perform automatic , remote , or
manual calibrations. Automatic and remote calibrations require a remote
calibration unit (RCU) that automatically switches the calibration gases,
and an auto calibration card installed in your control unit. Manual cali-
brations are performed without an RCU and you must switch the gases
manually.
Automatic Calibrations
Allows the system to calibrate itself. You define the calibration gas values,
the time each gas will flow through the sensor, and the frequencies at
which automatic calibrations will be performed (for example, every four
hours, every two days, etc.). The system will calibrate itself at those pre-
defined times. You can also use a digital input to activate an automatic
calibration or verification. See the “Remote Calibration Unit Connections”
section in the Installation chapter for help on how to use a digital input to
initiate an automatic calibration or verification.
Remote Calibrations
You define the calibration gas values but you interactively determine how
long each calibration gas should flow from the RCU and into the sensor by
pressing a key on the control unit.
M anual Calibration
You must physically switch the gases because you are not using an RCU.
However, you still define the calibration gas values.