SRS Labs SIM923 Manuale operativo
Operation and Service Manual
Pt RTD Monitor
SIM923
Stanford Research Systems
Revision 1.7 •May 8, 2007
Certification
Stanford Research Systems certifies that this product met its published specifications at the time
of shipment.
Warranty
This Stanford Research Systems product is warranted against defects in materials and workman-
ship for a period of one (1) year from the date of shipment.
Service
For warranty service or repair, this product must be returned to a Stanford Research Systems
authorized service facility. Contact Stanford Research Systems or an authorized representative
before returning this product for repair.
Information in this document is subject to change without notice.
Copyright c
Stanford Research Systems, Inc., 2003, 2007. All rights reserved.
Stanford Research Systems, Inc.
1290–D Reamwood Avenue
Sunnyvale, CA 94089 USA
Phone: (408) 744-9040 •Fax: (408) 744-9049
Printed in U.S.A. Document number 9-01557-903
SIM923 Pt RTD Monitor
Contents
General Information iii
Service .............................. iii
Symbols ............................. iv
Notation ............................. v
Specifications .......................... vi
1 Getting Started 1 – 1
1.1 Introduction to the Instrument . . . . . . . . . . . . . 1 – 2
1.2 Front-Panel Operation . . . . . . . . . . . . . . . . . . 1 – 2
1.3 Sensor Interface . . . . . . . . . . . . . . . . . . . . . . 1 – 4
1.4 SIMInterface........................ 1–6
2 Remote Operation 2 – 1
2.1 Index of Common Commands . . . . . . . . . . . . . . 2 – 2
2.2 Alphabetic List of Commands . . . . . . . . . . . . . . 2 – 4
2.3 Introduction ........................ 2–6
2.4 Commands......................... 2–7
2.5 StatusModel........................ 2–17
i
ii Contents
SIM923 Pt RTD Monitor
General Information
The SIM923 Pt RTD Monitor, part of Stanford Research Systems’
Small Instrumentation Modules family, consists of four channels of
sensor excitation and readout for precision low-noise resistive ther-
mometry. Independent 1 mA DC current sources provide sensor
excitations to the four-wire measurement circuits.
Service
Do not install substitute parts or perform any unauthorized modifi-
cations to this instrument.
The SIM923 is a single-wide module designed to be used inside the
SIM900 Mainframe. Do not turn on the power until the module is
completely inserted into the mainframe and locked in place.
iii
iv General Information
Symbols you may Find on SRS Products
Symbol Description
Alternating current
Caution - risk of electric shock
Frame or chassis terminal
Caution - refer to accompanying documents
Earth (ground) terminal
Battery
Fuse
On (supply)
Off (supply)
SIM923 Pt RTD Monitor
General Information v
Notation
The following notation will be used throughout this manual:
•Front-panel buttons are set as [Button];
[Adjust ] is shorthand for “[Adjust ] & [Adjust ]”.
•Front-panel indicators are set as Overload.
•Remote command names are set as *IDN?.
•Literal text other than command names is set as OFF.
SIM923 Pt RTD Monitor
vi General Information
Specifications
Performance Characteristics
Min Typ Max Units
Inputs Number of inputs 4
Sensor type Platinum RTD, other RTDs
Measurement type 4–wire
Excitation 4 constant current sources
0.999 1 1.001 mA DC
Sensor Characteristics Sensor units Ohms
Input Range 0 1400 Ω
sensor+lead resistance 1400 Ω
Calibration curves DIN 43760
4 user defined curves
Curve size (each) 256 points
Temperature range 20 873 K (typical)
sensor dependent
Measurement Display resolution 4 digits
Interface resolution 1 mΩ
1 mK
Measurement resolution 1.2 mΩrms
Measurement accuracy, (23 ±1)◦C 5 mΩ
Temperature coefficient −5+5 ppm/◦C
Operating Temperature 0 40 ◦C
Power ±15,+5 V DC
Supply current 50 (±15 V), 250 (+5 V) mA
General Characteristics
Interface Serial (RS-232) through SIM interface
Connectors 2 DB–9 (female)
4–wire measurement +ground (Ch 1 & 2)
4–wire measurement +ground (Ch 3 & 4)
DB–15 (male) SIM interface
Weight 1.4 lbs
Dimensions 1.500 W×3.600 H×7.000 D
SIM923 Pt RTD Monitor
1 Getting Started
This chapter gives you the necessary information to get started
quickly with the SIM923 Pt RTD Monitor.
In This Chapter
1.1 Introduction to the Instrument . . . . . . . . . . . . . 1 – 2
1.1.1 Overview ..................... 1–2
1.2 Front-Panel Operation . . . . . . . . . . . . . . . . . . 1 – 2
1.2.1 Excitation ..................... 1–2
1.2.2 Units........................ 1–2
1.2.3 Current reversal . . . . . . . . . . . . . . . . . . 1 – 3
1.3 Sensor Interface . . . . . . . . . . . . . . . . . . . . . . 1 – 4
1.3.1 Four-wire measurement . . . . . . . . . . . . . 1 – 4
1.3.2 Two-wire measurement . . . . . . . . . . . . . 1 – 5
1.4 SIMInterface ....................... 1–6
1.4.1 SIM interface connector . . . . . . . . . . . . . 1 – 6
1.4.2 Direct interfacing . . . . . . . . . . . . . . . . . 1 – 6
1–1
1–2 Getting Started
1.1 Introduction to the Instrument
The SIM923 Pt RTD Monitor monitors up to four (4) resistive tem-
perature detectors (RTDs) using a stable 1 mA DC current excitation.
1.1.1 Overview
The SIM923 uses a ratiometric design, where the excitation current
is passed through both an internal, stable reference resistor and the
user’s resistive thermometer. The instrument calculates the ratio
of the voltage across the user’s resistor to the voltage across the
reference resistor, multiplied by the (known) value of the reference
resistor, to obtain the user result.
Each channel has an independent current source and reference re-
sistor, so the excitation to the user’s sensor remains steady as the
SIM923 cycles between measurements. Disabling a channel switches
that channel’s current source off.
A precision 24–bit analog-to-digital converter is cycled between the
channels with a rate of 4 conversions per second. With all channels
enabled, a complete cycle is completed every second; disabling some
channels yields a corresponding increase in overall cycle rate.
1.2 Front-Panel Operation
The front panel of the SIM923(see Figure 1.1) provides a simple op-
erator interface.
1.2.1 Excitation
The four channels of the SIM923 Pt RTD Monitor can be indepen-
dently enabled or disabled from the front panel. Disabling a channel
turns offthe 1 mA excitation current to that sensor, and speeds the
readout rate for the remaining (enabled) channels.
To toggle the excitation for a channel, first briefly press [Excitation].
One of the four channel displays will appear highlighted, indicating
which channel is selected. Briefly tap [Excitation] to advance the
highlighted selection until the desired channel is selected. Then
depress and hold [Excitation] until the display switches between the
numerical value and the word .
1.2.2 Units
The SIM923 displays the sensor results either as resistance (in ohms)
or temperature (in kelvin). Pressing [Units] toggles between these
two modes; the active units are indicated by the illuminated Kor Ω.
SIM923 Pt RTD Monitor
Indice
Altri manuali SRS Labs Monitor
