5623B
Users Guide
4
Installation
Lead Wire Identification
The 5623B PRT is equipped with a four-wire cable (see Figure 1). 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 two different colors. Lead wire pairs attached to each
end of the sensor are identified by red and white insulation.
White
Red
White
Red
5623B Lead Wires.eps
Figure 1. PRT Schematic
PRT Care and Handling Guidelines
Caution
W
Read this section before removing the PRT from the shipping
box or case.
Care must be taken in handling the PRT to maintain calibration accuracy. Care should still be used
when handling the PRT even though the Inconel sheath is durable and provides good protection
for the sensor. Correct handling of the PRT will prolong the life expectancy. When not in use, the
PRT should be stored in an optional protective case that can be purchased by contacting Fluke
(see “How to Contact Fluke”). The handle is designed to be immersed.
PRT Handling Guidelines
•
Keep the thermometer as clean as possible.
•
Immerse the thermometer in the appropriate liquid for the temperature range. If a dry block
is used, the well diameter should allow the PRT to comfortably slip in and out without excess
movement. For best results, immerse the thermometer as deep as possible to avoid “stem
effect” (the temperature error caused by the conduction of heat away from the sensor).
•
Allow sufficient time for the thermometer to stabilize before making measurements. This
allows for the best accuracy.
•
Use the correct drive current with the thermometer to prevent error in temperature or
resistance. Fluke recommends 1 mA.
•
Use the protective shipping box provided or other protection when the thermometer is not in
use.
•
DO NOT
subject the thermometer to any physical shock or vibration.
•
DO NOT
use pliers or other devices to squeeze the sheath. This action can permanently
damage the PRT.
•
DO NOT
subject the thermometer to temperatures above the highest specified operating
temperature.
•
DO NOT
expose the thermometer’s handle or cables to extreme temperatures. The temperature
limits of the handle and cables are: –100 °C to 156 °C.
•
DO NOT
screw a clamp down so tight that it dents the sheath. This can permanently damage
the PRT.
