Pressure Measurement; Zero Calibration - YOKOGAWA MT210 User Manual

Pressure Measurement

Zero Calibration

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Zero calibration refers to corrections made to compensate for effects caused
by changes in temperature and the installation environment, in order to perform
measurement with high accuracy. Before starting measurement, make
sure that zero calibration (ZERO CAL) has been performed. Furthermore,
if operating conditions are likely to change, perform zero calibration again
periodically.
When Using the Gauge Pressure Model
1.
Open the pressure input port to the atmosphere.
2. Press the ZERO CAL.
3.
Zero calibration is performed after the buzzer sounds for approximately one
second.
When Using an Absolute Pressure Model (767357, 767367 or 767387)
To avoid operational error, zero calibration for the absolute pressure models
differ from that of the gauge pressure model.
1.
Connect a vacuum pump having a capacity of 1 Pa (7.5 × 10
the input port, create a vacuum, then perform zero calibration. Make sure that the
pipe between the pump and the instrument is as short as possible to increase the
degree of vacuum.
2. After the reference pressure value has become stable, hold down ZERO CAL for
five seconds.
3.
Zero calibration is performed after the beep sounds for approximately one second.
However, if the reference pressure value is 1 kPa higher or lower than the initial
value (factory setting), zero calibration is not performed and error code 17 is
displayed. Refer to 54 for error code information.
Note
• Zero calibration remains in effect even if a new unit of pressure is selected.
• Zero calibration cannot be performed until after the instrument has been warmed up.
• For measurement of liquid pressure, be sure to fill the pipes and instrument (measurement
section) with the liquid before starting zero calibration.
• If it is necessary to match the pressure reference with a gauge, such as a piston pressure
gauge whose pressure reference position is clear, align it with the reference point of the
pressure receiving section as shown below before starting zero calibration.
Pressure
Receiving Station
• When working with gauge pressure models, perform zero calibration whenever the operating
position is changed.
*1
Approx. 223 mm (Approx. 210 mm
*1: 767351, 55, 61, 65, 70, 71, 72, 73, 81
*2: 767353, 56, 57, 63, 66, 67, 83, 85, 86, 87
–3
torr) or higher to
*2
)
IM 767361-01E