Alpes Lasers . TC-3 Uživatelský manuál stáhnout pdf (Strana 25)

TC-3 Temperature Controller User’s Manual · Page 25

The TC-3 automatically determines which equation to use based on

the conditions at the time of the measurement.

2-Wire versus 4-Wire Measurements

One concern in using RTDs are their relatively low resistance (typically

100Ω at 0°C), and small Ω/°C. Because of these two factors, the

resistance of the cable used to connect to the sensor can become a

significant error in the sensor measurement. The TC-3 offers two RTD

measurement modes: a conventional two wire measurement mode,

which is subject to this error, and a four wire measurement mode that

uses separate sensor and source lines to remotely sense the actual

resistance of the RTD and eliminate the cable or connector resistances.

When using 4-wire measurement mode, you must select ‘RTD (4-wire)’

as the sensor type, and then connect the Sensor+ and Remote

Sensor+ at one side of the RTD, and Sensor– and Remote Sensor– to

the other side of the RTD. Make these connections as close to the

sensor as possible.

The drawings below illustrate how 2-wire and 4-wire connections work.

Note that 4-wire measurements require all four wires to be brought

through the cable to the mount. The 1262 and 1263 cables carry this

connection through to the mount, but the 1260 and 1261 cables do

not.

RTD 2-wire Measurement

RTD 4-wire Measurement

Mount5300

RTD

Sensor

Sensor+

Sensor–

5300

RTD

Sensor

Sensor+

Remote Sensor+

Remote Sensor–

Sensor–

Mount

1 2 ... 20 21 22 23 24 25 26 27 28 29 30 ... 40 41

Žádné komentáře

Alpes Lasers . TC-3 Uživatelský manuál Strana 25