THM1176/TFM1186 Use
r’s Manual
v 2.0 r 1.0
– 02/20
Copyright © 2020 Metrolab Technology SA
www.metrolab.com
12
o
THM1176-LF: millitesla fringe fields;
o
TFM1186: nanotesla-range perturbations
in, for example, the earth’s
field.
•
Bandwidth of DC to 1 kHz:
The 1 kHz bandwidth allows measuring AC fields generated, for example,
by transformers and motors.
•
Trigger modes:
Three trigger modes allow the acquisition procedure to be fine-tuned for the
measurement.
o
Immediate trigger mode:
Immediate trigger mode
– the default – starts an acquisition
sequence immediately upon receiving the measurement command.
o
Timed trigger mode:
Timed trigger mode is suitable for measuring rapidly varying fields.
The maximum sample rate
– writing data into the acquisition buffer –
is approximately 5.3 kSa/s, where one sample is a triplet (B
x
, B
y
,
B
z
). With a simultaneous readout via USB, the maximum sample
rate is approximately 2.3 kSa/s.
o
Bus triggered mode:
The USB bus trigger command can be used to synchronize the
acquisition with external events. The instrument allows up to about
400 bus triggers per second.
•
Measurement blocks:
The THM1176/TFM1186 contains a local memory capable of holding 4096
samples, allowing data to be acquired more quickly than it can be read out
by the USB interface.
•
Averaging:
Averaging, or oversampling, can reduce measurement noise. The degree
of averaging is controllable, since long integration periods might be
beneficial for static fields, but counterproductive for time-varying fields.