4
Installation
4.1
Environmental Issues
Ideally, temperature calibration equipment should be used in a calibration labo-
ratory or other facility specifically designed for this purpose. Environmental re-
quirements include:
•
Stable temperature and relative humidity <80%
•
Clean, draft-free area
•
Low noise level: low radio frequency, magnetic or electrical interference
•
Low vibration levels
•
Indoor use only
4.2
Mounting
Most often temperature standards, primary and secondary, are used to calibrate
other temperature-sensitive equipment. The PRT must be mounted carefully to
avoid any damage to the sheath or sensor. If the fluid bath used does not have a
lid designed for PRT insertion, clamps should be used to ensure the handle and
cable are not immersed.
Do not screw the clamps too tight. Over tightening
will damage the sheath.
If metal comparison blocks are used in the bath,
maintain a close fit between the thermometer sheath and the well in the com-
parison block. However, allow for the thermal expansion of the thermometer
sheath when determining block well tolerances.
4.3
Lead Wire Identification
The 5624 PRT is equipped with a four-wire cable. Four lead wires are used to
cancel lead wire resistance. For best results, the readout device should be
equipped to handle four-terminal resistors.
The lead wires are four different colors. Lead wire pairs attached to each end of
the sensor are identified by red and black heat shrink tubing.
13
4 Installation
Environmental Issues
BLACK
(Heat Shrink)
RED
(Heat Shrink)
Figure 3
PRT Schematic
