8 Way Selector Switches Models 954 and 958

 
Isotech produces two eight way selector switches, one for resistance thermometers Model 954 and Model 958 for thermocouples.

These switches have been designed for use in conjunction with our TTI range. The switches allow easy selection of connected sensors. They can be operated from either the front panel switch or from an RS232 interface that is provided as standard. Channel status is indicated via front panel LEDs. The Selector switches can be located adjacent to the sensors being calibrated, giving more flexibility than a permanently connected or stacked system.

The PRT Switch has 4mm terminal posts that can accept bare wires or 4mm plugs. The thermocouple switch has eight miniature thermocouple connectors. These thermocouple connectors are thermally bonded to a platinum resistance thermometer that measures the temperature of the connector and hence the “cold junction”.

The TTI range temperature indicators feature the ability to measure a remote cold junction and this permits a mixture of thermocouple types to be connected through the box. The I-Cal software supports Switchbox models 954 and 958 and, for automatic operation, two boxes can be connected together with a “master / slave” lead allowing them to be controlled from a single RS232 port and up to 16 sensors to be switched.

The software can automatically switch between the boxes and connect the appropriate output to the TTI. This 16 channel operation is not convenient without the software and manual operation of two boxes together is not recommended.
Technical Feature Value
Model 954 RTD Selector Switch 958 TC Selector Switch
Channels Eight - four wire (four pole) Eight - two wire (two pole)
Control Front panel switch and RS232 Front Panel switch and RS232 (Also compatible with Isotech VLT system)
Connectors 4mm Terminal Post Miniature Thermocouple Connectors
International Circuit Resistance <250mΩ <250mΩ
Thermal EMF, typical 2μV after 1 minute of channel set 6μV after 30 minutes of channel set 2μV after 1 minute of channel set 6μV after 30 minutes of channel set
Reference Junction Measuring Device 100Ω 1/10 Din Pt100 100Ω 1/10 Din Pt100
Thermal Coupling <0.2°C *Basis of test. At ambient 20°C ±2°C the internal Pt100 agreed with the connected thermocouples to ±0.2°C (including all measurement errors) using IEC584-1995 and IEC751-1995. The uncertainty of this test was ±0.3 <0.2°C *Basis of test. At ambient 20°C ±2°C the internal Pt100 agreed with the connected thermocouples to ±0.2°C (including all measurement errors) using IEC584-1995 and IEC751-1995. The uncertainty of this test was ±0.3
Power 5 VDC 100-250 VAC, 50/60Hz Power Supply Included 5 VDC 100-250 VAC, 50/60Hz Power Supply Included
Dimensions Height 91mm Width 141mm Depth 165mm Weight 1kg Height 64mm Width 141mm Depth 165mm Weight 1kg
How to order 954 TC Selector Switch 958 TC Selector Switch