Isotech TTI-7-R, Operator'S Handbook Manual

Page: 49 / 120

Operating the TTI-7-R
5.5.4 Using the measurement trigger function [Run/Hold]
The TTI-7-R default trigger mode is Run/Hold. It can also be
configured
to operate in single shot mode. Press the key to alternate
between continuous measurement (Run), and measurement hold
(Hold). Measurement hold mode stops all measurement operations,
freezing the current display value. It also halts all scanning and data
logging operations. When measurement hold is enabled, a
Hold
message is displayed on the bottom line.
Press 3/TRIG again to resume measurement, scanning or data
logging operations. A Run message is displayed on the bottom line
and the message Busy flashes on every time a new temperature
measurement is taken.
Setting the trigger mode to single shot mode is described in Section
5.6.3. In single shot mode, the TTI-7-R remains in the hold state until
you press the 3/TRIG key; it then captures a single
measurement reading.
If you have scanning enabled this allows you to single step through the
scanning routine.
If the data logger is enabled all the spot readings will be stored in the
data log memory.
5.5.5 Selecting PRT measurement sense current
PRT measurement uncertainty can be affected by external EMFs and
PRT self heating. The TTI-7-R allows you to select the measurement
sense current magnitude and polarity so that you can evaluate the
magnitude of such external factors.
a) Selecting positive measuring current polarity (+I)
Press /+1 for positive measuring current polarity. The
measurement time is approximately 1.8 seconds per reading for
channels A and B, and 3.6 seconds for Ch1-Ch2 relative
measurement.
Page 5-15