21
Phone:(910) 392
‐
2490
Fax: (910) 392
‐
2123
416 Landmark Drive
Wilmington, NC 28412
www.easterninstruments.com
RTD TEMPERATURE SENSOR INPUT
:
If the QVT is purchased as a mul variable transmi er with Temperature measurement, an RTD
sensor must be wired to the QVT. The QVT temperature input requires an insulated Pla num
Pt100 RTD sensor which will typically be Class A, 3 wire model (although 2 and 4 wire models
can also be used).
Typically, RTD’s have an insula on resistance of at least 100 mega ohms
‐
a lower insula on
resistance can lead to inaccuracies.
When extension wire is required for the connec on between the sensor head and transmi er,
22 or 24 AWG RTD extension wire is recommended. Use of the Shield is op onal, but recom
‐
mended. If used, the Shield must be grounded to the housing or head of the RTD, which in
turn, must be grounded.
DO NOT GROUND THE SHIELD TO THE QVT TRANSMITTER!
Although the QVT RTD input cancels lead resistance, it is best to use the minimum lead re
‐
sistance in case they are unequal. It is highly recommended to connect to ground the Shield
of longer cables, typically greater than 10 feet in length.
TYPICAL 3
‐
WIRE RTD INSTALLATION DIAGRAM
TYPICAL 2
‐
WIRE RTD INSTALLATION DIAGRAM
QVT
Transmi er
+
‐
White
Red
Red
Non
‐
Isolated RTD Input
Insulated RTD in head
Note: RTD wire colors
‐
EI uses the IEC standard of Red, Red, White where the
Red wires are common. Many other standards exist, but the common wires
are always the same color.
QVT
Transmi er
+
‐
White
Red
Red
Non
‐
Isolated RTD Input
Insulated RTD in head
Note: RTD wire colors
‐
EI uses the IEC standard of Red, Red, White where the
Red wires are common. Many other standards exist, but the common wires
are always the same color.
