Minebea DSA-631, Instruction Manual

Page: 35 / 64

25
4. MEASUREMENT
4-1. Cautions before Measureing (Refer to Table 4-1)
Before starting measurement, check the following points;
Items Cautions Reasons
Instalation environment for strain gage and bridge box.
The joints must be solered, and the connections must be
properly connected.
Prevents poor connections, noise, and
instability in operation.
The insulation resistance of strain gages must be equal
to or greater than 60 M
Ω
.
Prevents instability in operation as well as
noise from entering the equipment.
Installing the bridge box and strain gages in the
presence of strong magnetic or electric fields must be
avoided.
Prevents noise from entering the equipment.
Install the bridge box and strain gage in environments
where there is as little moisture as possible and the
ambient temperature is not high.
Prevents instability in operation.
The leads that connect strain gages to the bridge box
should be as short as possible and should be shielded.
Prevents reduction in the gage factor and
deterioration in output linearity. Prevents
noise from entering the equipment.
The interconnecting cable, which connects the bridge
box to the DAS-631 amplifier unit, should be as short as
possible (DAS-631 amplifier automatically compensates
for bridge voltage drops with its cable length
compensation.)
Prevents a bridge voltage drop, which may
result in an error between the signal and the
internal calibrator.
Installation environment for dynamic strain amplifier system
. The amplifier system must be used in environments
where the ambient temperature ranges from -10
 C to
50  C and the ambient humidity ranges from 20 % to
85%RH (with no condensing)
Prevents instability in operation
Install the amplifier system n envitonments where
accel- eration of mechanical vibratins is less than 3G (3
000 rpm, 0.6 mmp-p)
Prevents damage and noise from entering the
equipment.
Install the amplifier system in the presence of strong
magnetic or electric fields must be avoided.
Prevents noise from entering the equipment.
The housing case must be property grounded
(when the system operates on AC power)
Prevents noise from entering the equipment.
Operatin of dynamic strain amplifier system
Select the bridge suppy voltage in accordance with the
strain gage to be used.
Prevents measurement errors due to
generation of heat in strain gage.
The connector must be properly connected. Prevents instability in operation and poor
connections.
Care must be taken not to smear the input connector
with oil, dirt, or anything else.
Prevents instability in operatin and poor
connections.
Verify that the power supply voltage is within the range
of specifications
ＡＣ
85
~
132V,
ＡＣ
180
～
264V
ＤＣ
10
~
30V
Check that the polarity of the battery is correct,
especially when 12 VDC is used.
** If this amplifier is used in Japan domestic, the
voltage exceeding power supply voltage AC125 V
cannot be supplied from the limitation of “Electrical
Appliances and Material Safety Law”.
If the supply voltage is less than the lower
limit, failures in operation may occur. if the
suppy voltage is higher than the specified
upper limit, hear may be produced, which
may result in damaging electronic
components.
If the polarity of the battery is not correct, the
amplifier system will not operate. (However,
the system and the battery will not be
damaged though.)
Table 4-1 Precautions before measuring.