Probe Calibration - Presys T-350P Technical Manual

PRESYS
 Instruments
Input calibration for  is performed in two steps:
a) Application of mV signal:
For the calibration below, leave terminals RTD3 (+) and RTD4 (+) short-circuited.
mV Signal
V_OHM3
V_OHM4
b) Application of standard resistors:
Connect a decade box or standard resistors on terminals RTD1, RTD2, RTD3 and
RTD4 (4-wire connection).
resistors
The cold junction calibration (CJC) is performed measuring the mV(-) terminal
temperature. Store only the 1

7.2 - Probe Calibration

The options of calibration / probe are:
ºC: Adjust of the internal temperature sensor (internal Probe).
RESTORE: Restores the internal temperature sensor calibration parameters to
the factory values.
To readjust the internal Probe it is necessary to compare the value indicated by
the calibrator (Probe) and the temperature value from an external probe placed in the dry
block insert. The temperature of the external probe should have high accuracy and
should be measured by a superthermometer (ST).
The option to adjust the internal sensor has seven points of adjustment. These
points are recorded via keys 1 to 7.
Before starting the calibration (adjustment), record in these points the respective
initial storing values, according to the table below.
Go to the manual operating mode (menu EXEC) and generate all the seven levels
of temperature (setpoints from the table), writing down the value indicated by the
superthermometer (ST). Now, go back to the option Calibration/ Probe / ºC and record
the values indicated by the superthermometer.
Terminals
RTD3(+) and mV(-)
RTD4(+) and mV(-)
OHM3
OHM2
OHM1
st
point.
Cold Junction
CJC

ºC RESTORE
st
1 point
90.000 mV
90.000 mV
st
1 point
20.000 
100.000 
500.000 
st
1 point
32.03 ºC
T-350 P / T-650 P
nd
2 point
120.000 mV
120.000 mV
nd
2 point
50.000 
500.000 
2200.000 
Page 19