Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
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Transducers and Sensors<br />
Alarm Limits<br />
Introduction to the <strong>34980A</strong> 1<br />
Transducers and sensors convert a physical quantity into an electrical<br />
quantity. The electrical quantity is measured and the result is then<br />
converted to engineering units by the <strong>34980A</strong>'s main system processor.<br />
For example, when measuring a thermocouple, the instrument measures<br />
a dc voltage and mathematically converts it to a corresponding<br />
temperature in °C, °F, or K.<br />
<strong>Measure</strong>ment Typical Transducer Type Typical Transducer Output<br />
Thermocouple 0 mV to 80 mV<br />
Temperature<br />
Resistance temperature detector<br />
(RTD)<br />
2-wire or 4-wire resistance from 5 to 500<br />
Thermistor 2-wire or 4-wire resistance from 10 to 1M<br />
Pressure Solid state device ±10 VDC<br />
Flow Rotary type, thermal type 4 mA to 20 mA<br />
Strain Resistive elements 4-wire resistance from 10 to 10 k<br />
Events Limit switches, optical counters,<br />
rotary encoder<br />
0V or 5V pulse train<br />
Digital System status TTL levels<br />
The <strong>34980A</strong> has four alarms which you can configure to alert you when<br />
a reading exceeds specified limits on a channel during a scan. You can<br />
assign a high limit, a low limit, or both to any configured channel in the<br />
scan list. You can assign multiple channels to any of the four available<br />
alarms (numbered 1 through 4). For example, you can configure the<br />
instrument to generate an alarm on Alarm 1 when a limit is exceeded on<br />
any of channels 1003, 2025, or 3020.<br />
You can also assign alarms to channels on the digital modules (34950A<br />
and 34952A). For example, you can generate an alarm when a specific<br />
bit pattern or bit pattern change is detected on a digital input channel or<br />
when a specific count is reached on a totalizer channel. With the digital<br />
modules, the channels do not have to be part of the scan list to generate<br />
an alarm.<br />
<strong>Agilent</strong> <strong>34980A</strong> Mainframe User’s Guide 7