Teledyne 3020M - Explosion proof paramagnetic oxygen analyzer User Manual

Page 33

Percent Paramagnetic Oxygen Analyzer

Installation 3

3-11

Teledyne Analytical Instruments

3.3.9 Remote Sensor and Solenoid Valves

The 3020M is a single-chassis instrument, which has its own sensor

and, in the –C option, its own gas-control solenoid valves. The REMOTE
SENSOR connector is not used, and the SOLENOID RETURN connectors
are used (without the –C option) to synchronize external gas control valves.
See Figure 3-7.

Figure 3-7: Remote Solenoid Return Connector Pinouts

The voltage from these outputs is nominally 0 V for the OFF and

15 V dc for the ON conditions. The maximum combined current that can be
pulled from these output lines is 100 mA. (If two lines are ON at the same
time, each must be limited to 50 mA, etc.) If more current and/or a different
voltage is required, use a relay, power amplifier, or other matching circuitry
to provide the actual driving current.

In addition, each individual line has a series FET with a nominal ON

resistance of 5 ohms (9 ohms worst case). This could limit the obtainable
voltage, depending on the load impedance applied. See Figure 3-8.

Figure 3-8: FET Series Resistance

+15 VDC

SAMPLE (return)

SPAN (return)

ZERO (return)

EXHAUST (return)

Matching

Circuitry

(If

Necessary)

16-2
15-2
14-2
13-2

16-1
15-1
14-1
13-1

Remote Solenoid 1

Remote Solenoid 4

Remote Solenoid 3

Remote Solenoid 2