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HUGO SACHS ELEKTRONIK - HARVARD
A P P A R A T U S
GmbH D-79232 March-Hugstetten Germany
HSE PLUGSYS
®
TAM-A Type 705/1 and TAM-D Type 705/2
6. Start-up
After you have completed the module installation, connected the transducer to the TAM, switch on the power on
the housing. The first step is to calibrate the TAM to the transducer. This may involve adjusting the gain of the
TAM to suit the transducer sensitivity and the required range. In addition the CAL Value (simulated static value
e.g,. 100mmHg) for calibrating the recording system has to be set.
.
6.1 Transducer calibration
The following points have to be considered first:
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Establish the required measuring range, e.g. ±200 mmHg. Note that the maximum
expected signal has to be smaller than the selected range. Do not oversee the pulsatile part of the signal
(e.g. the systolic diastolic pulsation of blood pressure). Also have in mind that testing a drug may increase
dramaticaly the signal amplitue. Note, that the selected range should be 10 -20 % higher than the maxi-
mum expected signal.
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Output voltage corresponding to the selected range (i.e. to ±200 mmHg).
Important
The signal voltage span of the PLUGSYS measuring system is fixed at ±10 Volt. The goal
should always be to produce maximum amplifier output to have the best ratio between useful
signal and resolution. It means that under ideal conditions the range corresponds to the
output voltage of ±10 Volt. On TAM-A there is a further advantage through the better deflec-
tion of the bar graph indication. The dynamic (pulsatile part) of the measured signal is much
better seen.
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Determine the calibration signal, e.g. 100mmHg, for calibrating the recording system to
which TAM is connected. By switching the operating mode from MEASURE to OFF and
then to CAL it is possible to simulate a static value of e.g. 100 mmHg.
6.1.1 Basic settings for transducer calibration
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Set output filter to 300 Hz
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Set operating mode to MEASURE
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Set GAIN 20-100% to 100%, fully clockwise (clicking noises) on the multi-turn trimmer
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Set fine manual zero adjustment to mid-position (19 turns anticlockwise and then 9 turns clockwise)
Initialize the autozero function to the mid of the calibration range. To do so start the autozero function with
the transducer disconnected. Since no transducer is connected to the TAM, zeroing is not possible and
the function is aborted with an error message. In that case the autozero function is normalised to its mid
setting. This procedure is essential to ensure that during later operation the autozero function has maxi-
mum action in both positive and negative direction. After this adjustment, connect the transducer back to
the TAM.
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Since the zero of most transducers is affected by its position, the transducer should during calibration be
secured on the bench in its operating position, e.g. by a stand, clamp or some suitable component.
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On the TAM-D the adjustment ADJ. next to the digital display, a multi-turn trimmer, must be turned fully
clockwise (clicking noises). The indicated value, referred to the output voltage, corresponds to 10 Volt =
1000 or 100% of the maximum possible range. The position of the decimal point is disregarded.
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See also the description of the autozero function below (Section 7.2).
It is essential that the housing of the input plug is screwed to the socket on the front panel.
This is necessary to ensure a secure connection between cable screen and transducer
housing screen. Protection against electrostatic discharges is ensured only when the plug
case has been properly screwed to the socket.
Important
If you bought the transducer together with the TAM amplifier module these settings already have been
done in the factory. See handwritten texts on TAM frontpanel.
Furthermore it is assumed that the internal GAIN jumper already has been set according chapter 4.2.4
