Measurement Computing Personal Daq rev.6.0 - Manual (Page 27)

Personal Daq User’s Manual 878595 General Information & Specifications 2-7
Automatic Calibration
The Personal Daq module contains a built-in source for performing automatic self-calibrations. These
calibrations can be performed between scans periodically throughout the measurement process, as
indicated in the following figure. Such calibration ensures accurate measurements, even in environments
that experience significant temperature fluctuations.
With exception of an automatic initial calibration, Personal Daq’s self calibrations are optional, and may
be discontinued (automatically) if the maximum sampling rate is used. This is because the time between
scans can become too short to permit calibration. In this instance, the PC can initiate calibration
immediately prior to the measurement process (see example 3 in the following figure).
Note: The continuous calibration feature is selected (or deselected) from the Configure Acquisition dialog
box. See Chapter 4 for more information.
Three Examples of Calibration/Scan Arrangements
Thermocouple Measurements
Personal Daq provides effortless thermocouple (TC) measurements. The unit includes built-in cold-
junction compensation (CJC), which is automatically invoked when you select TC measurements. The
Personal Daq automatically converts acquired voltage readings into compensated-linearized temperature
readings. A Personal Daq system can make thermocouple and volts measurements concurrently.