SRS Labs PTC10 User manual

Version 4.2 (May 14, 2019)
User Manual
PTC10
Programmable Temperature Controller

PTC10 Programmable Temperature Controller
Certification
Stanford Research Systems certifies that this product met its published specificationsat the timeof shipment.
Warranty
This Stanford Research Systems productis warrantedagainst defects in materials and workmanship fora period of
one (1) year from the date ofshipment.
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 © Stanford Research Systems, Inc., 2018. All rights reserved.
Stanford Research Systems, Inc.
1290-C Reamwood Avenue
Sunnyvale, California 94089
Phone: [phone]
Fax: [phone]
www.thinkSRS.com
Printed in the USA

Contents i
PTC10 Programmable Temperature Controller
Contents
Safety and preparation for use.......................................................................................v
Specifications ..................................................................................................................vii
Introduction 1
I/O cards ............................................................................................................................2
PTC320 thermistor/diode/RTD card.................................................................................... 2
PTC321 RTD reader................................................................................................................ 5
PTC323 2-channel thermistor/diode/RTD card................................................................... 6
PTC330 thermocouple reader.............................................................................................. 11
PTC420 AC output card........................................................................................................ 13
PTC430 50 W DC output card............................................................................................. 14
PTC431 100W DC output card............................................................................................ 15
PTC440 TEC driver ...............................................................................................................17
PTC510 analog I/O card....................................................................................................... 20
PTC520 digital I/O card........................................................................................................20
Operation 23
Quick start tutorial ........................................................................................................24
Turn the instrument on.......................................................................................................... 24
The Select screen...................................................................................................................24
Configure the sensor inputs................................................................................................... 24
If the sensor reading does not appear................................................................................... 25
Plot data.................................................................................................................................. 25
Test the outputs.....................................................................................................................26
Set the data logging rate.........................................................................................................27
Save data to and retrieve data from a USB memory device................................................27
Interface with a computer...................................................................................................... 28
Control a temperature........................................................................................................... 29
Acquiring and logging data ...........................................................................................36
Input filters..............................................................................................................................36
Custom calibration tables...................................................................................................... 36
Virtual channels ...................................................................................................................... 38
Logging data to internal memory........................................................................................... 39
Logging data to USB...............................................................................................................39
ADC sampling and logged data .............................................................................................39
Format of PTC10 log files...................................................................................................... 40
Using the system fan .....................................................................................................41
Using PID feedback........................................................................................................42
...................................................................... 42
Basic PID feedback concepts................................................................................................. 42
Manual tuning..........................................................................................................................43
Automatic tuning algorithms..................................................................................................46
Using the automatic tuner......................................................................................................49
Front-panel controls......................................................................................................52

Contents ii
PTC10 Programmable Temperature Controller
USB logging indicator .............................................................................................................52
.............................................................................................................................. 52
.............................................................................................................. 52
.......................................................................................................................53
..................................................................................................................54
........................................................................................................................... 54
................................................................................................................... 59
...................................................................................................................64
..................................................................................................................... 78
Firm ware updates..........................................................................................................85
Replacing the clock battery..........................................................................................86
Remote programming 87
Connecting to the PTC10...................................................................................................... 87
Communication, assembly, and run-time errors.................................................................. 90
Concurrent macros................................................................................................................90
Macro names.......................................................................................................................... 91
Command syntax ...................................................................................................................91
Rem ote instructions ......................................................................................................95
General instructions............................................................................................................... 95
IEEE 488.2 Instructions........................................................................................................... 99
Program submenu................................................................................................................103
System submenu...................................................................................................................106
<channel> submenu............................................................................................................110
Error codes...........................................................................................................................121
Startup macro.......................................................................................................................122
Sample macros.............................................................................................................123
Temperature profiles...........................................................................................................123
Control a feedback setpoint with an analog input..............................................................124
PID input scheduling.............................................................................................................124
Show channels with tripped alarms on the Numeric screen .............................................125
Make a virtual channel show the PID setpoint....................................................................125
Linearizing outputs when interfacing with external power supplies..................................125
Control instrument functions with the digital IO lines .......................................................126
Drive a solid state relay with the digital IO lines.................................................................127
PC applications 129
PTCFileConverter .......................................................................................................130
FileGrapher...................................................................................................................132
File menu...............................................................................................................................132
Edit menu..............................................................................................................................132
Process menu.......................................................................................................................134
Special menu.........................................................................................................................136
Command line and macro instructions...............................................................................137
Circuit description 141
Core system cards .......................................................................................................142
PTC212 CPU board.............................................................................................................142
PTC221 backplane...............................................................................................................142

Contents iii
PTC10 Programmable Temperature Controller
PTC231 front panel..............................................................................................................144
PTC240 GPIB card...............................................................................................................145
I/O cards........................................................................................................................146
PTC320 1-channel thermistor/diode/RTD reader...........................................................146
PTC321 4-channel RTD reader...........................................................................................147
PTC330 thermocouple reader............................................................................................148
PTC420 AC output card......................................................................................................149
PTC430 50W DC output card............................................................................................149
PTC431 100W DC output card..........................................................................................150
PTC440 TEC driver .............................................................................................................151
PTC510 analog I/O card.....................................................................................................152
PTC520 digital I/O card......................................................................................................153
Parts List 155
PTC212 CPU board.............................................................................................................155
PTC221 backplane...............................................................................................................165
PTC231 front panel..............................................................................................................167
PTC240 GPIB option...........................................................................................................169
PTC320 1-channel thermistor, diode, and RTD reader ....................................................170
PTC321 4-channel RTD reader...........................................................................................173
PTC330 thermocouple reader............................................................................................176
PTC420 AC output card......................................................................................................180
PTC430 50W DC output card............................................................................................182
PTC440 TEC driver .............................................................................................................184
PTC510 analog I/O card.....................................................................................................187
PTC520 digital I/O card......................................................................................................189
Schematics 193

Safety and Preparation for Use v
PTC10 Programmable Temperature Controller
Line voltage
The PTC10 operates from an88 to 264 VAC power source having a line frequency between 47
and 63 Hz.
Power entry module
A power entry module,labeledAC POWER onthe backpanelof the PTC10, provides
connection to the power source and to a protective ground.
Power cord
The PTC10 package includes a detachable, three-wire power cord for connection to the power
source and protective ground.
The exposed metal parts of the box are connected to the power ground to protect against
electrical shock. Always use an outlet which has a properlyconnected protective ground. Consult
with an electrician if necessary.
Grounding
A chassis grounding lug isavailable on the back panel of the PTC10. Connect a heavy duty
ground wire, #12AWG or larger, from the chassis ground lug directly to a facility earth ground to
provide additional protection against electrical shock.
Line fuse
Use a 10 A/250 V 3AB Slo-Blo fuse.
Operate only with covers in place
To avoid personal injury, do not remove theproduct covers or panels. Do not operate the
product withoutall covers andpanels inplace.
Serviceable parts
The PTC10 does not includeany user serviceableparts inside. Refer service toa qualified
technician.

Specifications vii
PTC10 Programmable Temperature Controller
PTC10 temperature controller
Maximum PID rate 50 or 60 Hz, depending on AC line frequency
Data logging rate 10 samples/second/channel 1 sample/hour/channel (can be set
independently for each channel or globally for all channels)
Display resolution 0.001 °C, °F, K, V, A, W, etc. if 1000 < displayed value < 1000;
6 significant figures otherwise
PID feedback auto-tuning Single step response or relay tuning with conservative, moderate, and
aggressive response targets
Display 320 × 240 pixel touchscreen; numeric and graphical data displays.
Alarms Upper and lower temperaturelimits or rate-of-change limits can be set on each
channel. If exceeded, an audio alarm and a relay closure occur.
Computer interface USB, Ethernet, and RS-232; optional GPIB (IEEE488.2)
Power 10 A, 88 to 132 VAC or 176 to 264 VAC, 47 to 63 Hz or DC
Dimensions 17"× 5" × 18" (WHL)
Weight 25 lbs.
Warranty One year parts and labor on defects in material and workmanship.
PTC320 thermistor, diode, and RTD reader
Inputs One input for 2-wire or 4-wire thermistor, diode, or RTD
Connector 6-pin 240° push-pull DIN socket
Thermistors
Range 0 30, 100, 300 ; 1, 3, 10, 30, 100, 300 k ; 2.5 M
Excitation current
30 range 200 µA
100 range 100 µA
300 range 50 µA
1 k range 30 µA
3 k range 20 µA
10 k range 10 µA
30 k range 5 µA
100 k range 3 µA
300 k range 2 µA
2.5 M range 1 µA
Initial accuracy
30 range ±0.025
100 range ±0.06
300 range ±0.1
1 k range ±0.2
3 k range ±0.6
10 k range ±1.3
30 k range ±4
100 k range ±10
300 k range ±250
2.5 M range ±30 k
Drift due to temperature
30 range ±0.002 /°C
100 range ±0.006 /°C
300 range ±0.006 /°C
1 k range ±0.01 /°C

Specifications viii
PTC10 Programmable Temperature Controller
3 k range ±0.03 /°C
10 k range ±0.1 /°C
30 k range ±0.15 /°C
100 k range ±0.5 /°C
300 k range ±3 /°C
2.5 M range ±2000 /°C
RMS noise
30 range 0.003
100 range 0.006
300 range 0.012
1 k range 0.02 (= 2 mK for 300 thermistor at 25°C)
3 k range 0.03 (= 0.8 mK for 1 k thermistor at 25°C)
10 k range 0.06 (= 0.6 mK for 2252 thermistor at 25°C)
30 k range 0.1 (= 0.3 mK for 10 k thermistor at 25°C)
100 k range 0.3 (= 0.2 mK for 30 k thermistor at 25°C)
300 k range 3 (= 0.7 mK for 100 k thermistor at 25°C)
2.5 M range 25 (= 1.8 mK for 300 k thermistor at 25°C)
Diodes
Excitation current output 10 µA
Initial accuracy ± 100 ppm
Drift ±5 ppm/°C
Voltage input 0 2.5 V
Initial accuracy 10 µV + 0.01% of reading
Drift ±5 ppm/°C
RMS noise 1.5 µV
RTDs
Range 0 30, 100, 300 ; 1, 3, 10, 30, 100, 250 k , 2.5 M
Excitation
30 range 3 mA
100 range 2 mA
300 range 1 mA
1 k range 500 µA
3 k range 200 µA
10 k range 100 µA
30 k range 50 µA
100 k range 10 µA
300 k range 5 µA
2.5 M range 1 µA
Initial accuracy
30 range ±0.004
100 range ±0.008
300 range ±0.02 (=±50 mK for Pt100 RTD at 25°C)
1 k range ±0.04
3 k range ±0.1
10 k range ±0.2
30 k range ±1
100 k range ±2.5
300 k range ±16
2.5 M range ±30 k
Drift due to temperature
30 range ±0.0006 /°C
100 range ±0.001 /°C
300 range ±0.0015 /°C (=±5 mK/°C for Pt100 RTD at 25°C)
1 k range ±0.005 /°C
3 k range ±0.01 /°C
10 k range ±0.03 /°C

Specifications ix
PTC10 Programmable Temperature Controller
30 k range ±0.06 /°C
100 k range ±0.2 /°C
300 k range ±3 /°C
2.5 M range ±2000 /°C
RMS noise
30 range 0.00012
100 range 0.0003
300 range 0.0006 ( = 1.4 mK for Pt100 RTD at 25°C)
1 k range 0.0013
3 k range 0.003
10 k range 0.006
30 k range 0.012
100 k range 0.07
300 k range 0.25
2.5 M range 25
PTC321 Pt RTD reader
Inputs Four 4-wire inputs for 100 Pt RTDs
Connector 5-pin, 3.5mm header
Range 0 400
IEC751 Pt100 RTDs 215 °C to 850 °C
Excitation current 1 mA
Initial accuracy ±30 mK
Drift due to temperature 1.4 mK/°C
Drift due to time ±15 mK/year (at 25°C ambient temperature)
Noise 2 mK RMS (at 25°C sensor temperature and 10 samples/s)
Signal detection Card detects open and short circuit conditions
PTC323 thermistor, diode, and RTD reader
Inputs Two inputs for 4-wire thermistor, diode, or RTD
Connectors One 9-pin D-sub socket
RTDs and thermistors
Range 0 10, 30, 100, 300 ; 1, 3, 10, 30, 100, 300 k ; 2.5 M , or auto
Excitation current Low power High power
10 range 1 mA 3 mA
30 range 300 µA 3 mA
100 range 100 µA 2 mA
300 range 30 µA 1 mA
1 k range 10 µA 500 µA
3 k range 3 µA 200 µA
10 k range 1 µA 50 µA
30 k range 300 nA 50 µA
100 k range 100 nA 5 µA
300 k range 30 nA 5 µA
2.5 M range 1 µA 1 µA
Initial accuracy (AC current, at midrange)
10 range ±0.007 ±0.005
30 range ±0.03 ±0.005
100 range ±0.07 ±0.008
300 range ±0.25 ±0.015 (=±40 mK for Pt100 RTD at 25°C)
1 k range ±0.6 ±0.05
3 k range ±2 ±0.1

Specifications x
PTC10 Programmable Temperature Controller
10 k range ±6 ±0.25
30 k range ±25 ±1
100 k range ±150 ±4
300 k range ±1 k ±13
2.5 M range ±3 k ±3 k
Typical drift due to temperature (at midrange)
10 range ±0.0002 /°C ±0.0001 /°C
30 range ±0.0004 /°C ±0.0001 /°C
100 range ±0.002 /°C ±0.0002 /°C
300 range ±0.004 /°C ±0.0004 /°C
1 k range ±0.01 /°C ±0.001 /°C
3 k range ±0.06 /°C ±0.003 /°C
10 k range ±0.2 /°C ±0.01 /°C
30 k range ±1 /°C ±0.02 /°C
100 k range ±3 /°C ±1 /°C
300 k range ±20 /°C ±2 /°C
2.5 M range ±30 /°C ±50 /°C
RMS noise (DC current, at midrange)
10 range 0.0003 0.0001
30 range 0.001 0.0001
100 range 0.002 0.0002
300 range 0.006 0.0003 ( = 0.8 mK for Pt100 RTD at 25°C)
1 k range 0.02 0.0007
3 k range 0.06 0.002
10 k range 0.2 0.007
30 k range 1.0 0.008
100 k range 6 0.12
300 k range 40 0.2
2.5 M range 10 10
Diodes
Excitation current output 10 µA
Initial accuracy ± 100 ppm
Drift ±5 ppm/°C
Voltage input 0 2.5 V
Initial accuracy 10 µV + 0.01% of reading
Drift ±5 ppm/°C
RMS noise 3 µV
PTC330 thermocouple reader
Inputs Four optoisolated thermocouple inputs
Connector Mini thermocouple jacks
Thermocouple types E, J, K, N, or T
Range ±500 mV
Type E 270 °C to 980 °C (range of calibration table with cold junction at 25°C)
Type J 210 °C to 1177 °C
Type K 270 °C to 1342 °C
Type N 270 °C to 1281 °C
Type T 270 °C to 383 °C
Input capacitance <1 pF
Accuracy ±500 mK (over 12 months)
Noise 20 mK RMS (at 10 samples/s)
Drift due to temperature 20 mK/°C (type K thermocouple at 164.0 K)
CMRR 100 dB
Common mode isolation 250 VAC

Specifications xi
PTC10 Programmable Temperature Controller
PTC420 AC output card
Output One line voltage output switched by solid-state relay
Connector NEMA 5-15 (3-prong North American wall socket); a heater cable with a
mating plug on one side and stripped ends on the other is included
Output voltage 120/240 VAC
Max. output current 5 A
On/off cycle time Adjustable between 1 and 240 s
Max. line voltage 250 VAC
Surge current 100 A max. (non-repetitive)
Output resolution 0.1% at 10 s cycle time
Heater resistance (min.) 24 (110 VAC), 46 (230 VAC)
PTC430 50 W DC output card
Output One linear, unipolar DC current source
Connector Two banana jacks, 0.75 inch center-to-center spacing
Range 50 V 1A, 20 V 2 A, 50 V 0.5A, 20 V 0.5 A,50 V 0.1A, or 20 V 0.1 A
Output resolution 24 bits with dithering enabled or 16 bits with dithering disabled
Accuracy ±1 mA (1 A range)
±0.1 mA (0.5 A range)
±0.01 mA (0.1 A range)
Noise (rms), 50 load, 6 µA (50 V 1 A and 20 V 2 A ranges)
DC 10 Hz 1.5 µA (0.5 A range)
0.2 µA (0.1 A range)
PTC431 100W DC output card
Output One unipolar DC current source
Connector #6 screw terminals. Accepts 12 22 AWG wire or #6 spade terminals up to
-lb.
Range 50 V 2A, 50V 0.6A, 50V 0.2A, 20V 2A, 20V 0.6A, 20V 0.2A
Output resolution 16 bits
Accuracy ±1 mA (2 A range)
±0.5 mA (0.6 A range)
±0.2 mA (0.2 A range)
Noise (rms), 25 load, 5 µA (2 A range)
DC 10 Hz 1.5 µA (0.6 A range)
0.5 µA (0.2 A range)
PTC440 TEC driver
Output One linear, bipolar DC current source
Input One 2- or 4-wire thermistor/RTD/IC temperature sensor input
Connector One 15-pin DB15-F
TEC driver
Output current -5 A +5A
Maximum power 50W
Compliance voltage 12 V (at 0 A current)
Output resolution 0.15 mA
Accuracy ±5 mA
Current noise 0.02 mA (at 0.5A current, 22 ohm resistive load, 0.01-10 Hz bandwidth)

Specifications xii
PTC10 Programmable Temperature Controller
Tem perature sensor input
Compatible sensors
Thermistors 2 or 4-wire NTC thermistors
RTDs 4-wire platinum RTDs, 100 1000 at 0°C
IC sensors LM335, AD590, or equivalent
Excitation current 10 µA, 100 µA, or 1 mA
Input range
Resistance 1 250 k
Voltage 0 2.5V
Current 0 1 mA
RMS electronic noise (sensor at 25°C)
10 µA excitation
1 k thermistor 0.7 = 15 mK
2252 thermistor 0.6 = 5 mK
10 k thermistor 1 = 4 mK
100 µA excitation
1 k thermistor 0.1 = 1.5 mK
2252 k thermistor 0.1 = 0.7 mK
10 k thermistor 0.2 = 0.5 mK
1 mA excitation
100 Pt RTD 0.003 = 8 mK
LM135/235/335 4 mK RMS
AD590/592 6 mK RMS
Initial accuracy
10 µA excitation
1 k thermistor 1.2 = 30 mK
2252 thermistor 10 = 100 mK
10 k thermistor 66 = 150 mK
100 µA excitation
1 k thermistor 0.06 = 1.6 mK
2252 k thermistor 0.1 = 10 mK
10 k thermistor 0.5 = 1.1 mK
1 mA excitation
100 Pt RTD 0.004 = 5 mK
LM135/235/335 70 mK
AD590/592 400 mK (sensor at 25°C)
Thermal drift
10 µA excitation
100 µA excitation
1 mA excitation
LM135/235/335
AD592/592
Analog I/O
Inputs/outputs 4 voltage I/O channels, independantly configurable as inputs or outputs
Connector 4 BNC jacks
Range ±10 V
Resolution 24-bit input, 16-bit output
ADC noise 30 µV RMS = 100 µV p-p (10 samples/s)
Digital I/O
Digital I/O
Inputs/outputs 8 optoisolated TTL lines, configurable as either 8 inputs or 8 outputs

Specifications xiii
PTC10 Programmable Temperature Controller
Connector One DB-25F
Relays
Outputs 4 independent SPDT relays
Connector One 12-pin 3.5mm header
Maximum current 5 A
Maximum voltage 250 VAC

Introduction 1
PTC10 Programmable Temperature Controller
Introduction
The PTC10 is a high-performance, general-purpose laboratory temperature controller that can
monitor and control temperatures with millikelvin resolution. Its features include:
Modular design
The PTC10 can accept up to four I/O cards, each of which can read up to four temperature
sensors and/or drive one heater. The instrumentcan be customized by selecting the I/O cards best
suited to yourapplication. The PTC10 also comes standard with four ±10V I/O channels that can
be used with external amplifiers toread signals and drive heaters.
Reads up to 16 temperature sensors
Temperature input cards are available for reading thermocouples, RTDs, thermistors, and
diodes. For optimal signal-to-noise ratio, each temperature input channel has its own 24-bit ADC.
Drives up to 6 heaters
Three kinds of heater driver cards are available for drivingresistive heaters and thermoelectric
devices. Depending on the model of driver card used, two or three heaters can be directly driven at
full power. In addition,the unpowered voltage I/O channels included asstandard equipment can
be used to drive heaters with the help of an external amplifier.
Graphical touchscreen display
The PTC10 can display temperature measurements and heater output on graphs or numeric
displays. Any combination of channels canbe displayed,and four differentchannel combinations
can be saved and recalled. Touchscreen operation makes theinstrumentversatile and easy to use.
Logs data to USB memory devices
Up to 10 data points/second/channel can be logged tostandard USB memory sticks and hard
drives. The data can be transferred to a computer by simply plugging the USB device into a PC and
copying the log files. Windows applications are included to graph PTC10 log files and to convert
them to various ASCII text formats.
Up to 6 feedback loops
The PTC10 cancontrol up to six different temperatures (one for eachheater output) by
continually adjusting theamount of power supplied to heaters. Each feedback loop can runas fast as
50 or 60 Hz, depending on the frequency of your AC power.
Runs user programs
A macro programming language makes it possible tocustomize the functionality of the
instrument. Conditional statements, variables, and subroutine calls are supported. Up to 10 user
programs can run concurrently.
Com puter communications
The PTC10 can receive text commands andsend responsesover USB, RS-232, Ethernet, and an
optional GPIB interface. All aspects of PTC10 operation canbe controlled over these interfaces.
Eight digital I/O linesare alsoprovided; these caninteract with user programs to control most
aspects

Introduction 2
PTC10 Programmable Temperature Controller
on removable circuit boards. The chassis has
four wide and two narrow slots for these I/O cards. The wide slots (which are labeled 1 4 on the
back panel) can be occupied by optionaltemperature inputand/or heater driver cards. The narrow
slots (slots 5 and 6)are occupied by general-purpose analogand digital I/O cards included as
standard equipment.
Replacing I/O cards
Cards can be added, removed, or rearranged by the user. No firmware setup is needed; the
system automatically recognizes the new cards. For most purposes, the sixslots are identical and
cards do not needto be arranged in any particularorder. However, the lower-numbered slots are
preferred for output cards because these slots get the most cooling from the fan. In addition, alarms
can only activate relays on a digital I/O card if the card is installed in slot 6.
Some channel-specific settings (PID feedback parameters, alarm settings, sensor type, custom
calibration data, and filter settings) maybe lost when I/O cards are replaced or rearranged.
However, factory calibration is stored on the card and is not lost.
To add or replacean I/O card:
1. Unplug the PTC10 from the wall; otherwise, even if the instrumentis switched off, live line
voltage could be present. Removing and installing I/O cardswhile the power is turned on
may permanently damage the instrument. large Philips head screws on the
sides of the cover and liftingthe cover straight up.
3. Remove the two flathead Phillips screws immediately t
back panel.
4. Remove the I/O card by pulling up alternately on the front and back of the card.
5. Install the new I/O card. Put the back of the card in place first, then press firmly down on
the front of the card. Ensure that the top of the card is level with the tops of all the other
cards.
6. Re-install the two back-panel screws and re-attach the top cover. The card can be damaged
if the screws are not installed.
7. Turn the PTC10on. The new card should automaticallyappear on theSelect screen, and
remote commands for the new card should automatically become available.
PTC320 thermistor/diode/RTD card
The PTC320 is a single-channel, multi-range input card that can read a variety of temperature
sensors. It can read resistances between 1 and 2.5 M , and can also read diode temperature
sensors.
Standard calibration curves are included for the following sensors.
the range of the standard calibration curve; outside this range, no reading appears for the sensor. It
may be possible to obtain a larger range by uploadinga custom calibration curve.

Introduction 3
PTC10 Programmable Temperature Controller
Sensor
class
Manufacturer
Calibration
type
Range,
K
Diode
Scientific Instruments
Si410
1.0 450
Si430
1.0 400
Si440
1.0 500
LakeShore; Omega
DT-470 (=CY7)
1.4 475
DT-670 (=CY670)
1.4 500
Cryo-Con
S700
1.5 475
S800
1.4 385
S900
1.5 500
Ruthenium
oxide
LakeShore
RX-102A
0.050 40
RX-103A
1.2 40
RX-202A
0.050 40
Scientific Instruments
RO600
1.0 300
Cryo-Con
R400
2.0 273
R500
0.050 20
RTD
All
IEC751 (DIN43760)
48.15 1173.15
US
48.15 1173.15
Thermistor
Measurement
Specialties,
Inc.
(formerly YSI);
Omega
100 
193.15 373.15
300 
193.15 373.15
1000 
193.15 373.15
2252 
193.15 523.15
3000 
193.15 523.15
5000 
193.15 523.15
6000 
193.15 523.15
10000  type B
193.15 523.15
10000  type H
193.15 523.15
30 k
233.15 523.15
100 k
233.15 423.15
300 k
298.15 423.15
1 M
298.15 423.15
Other resistive and diode sensors can be used with the PTC320, but require custom calibration
curves. For example, rhodium-iron, germanium, and carbon-glass sensors have too much sensor-
to-sensor variability to use a standard curve, and therefore must be custom-calibrated.
Connecting the sensor
The PTC320 hasa 6-pin DIN socket that mates withstandard6-pin push-pull DIN plugs (i.e.
Digi-Key CP-1060-ND). Thisis the pinoutof the socket, as it appears when lookingat the back
panel:
1
5
4
2
6
3Not connected
Excitation +Sense +
Ground
Excit

Introduction 4
PTC10 Programmable Temperature Controller
chassis.
The PTC320 passes anexcitation currentthrough theattached RTD, thermistor, or diode, and
senses the induced voltage. For the most accurate results all sensors should be read with a four-wire
configuration, using separate sense and excitation leads. However, for convenience the PTC320
can also read sensors attachedwith only two leads.
To make a two-wire measurement, connect one end of thesensor to pin 1(Excitation ) and the
other to pin 5 (Excitation +). An inaccuracy is introduced because the resistance of the leads affects
the measurement; however, some thermistors have such a high resistance that the lead resistance
may be negligible in comparison.
A four-wire measurement eliminates theeffect of leadresistance. In the four-wire configuration,
two of the wires carrythe excitation current, while the other two wiressense the voltage that the
current produces across the sensor. RTDs sold with four wires normally havetwo wires ofone
color, both attached to one side of the RTD, andtwo of a different color attached to the other side.
In this case, the RTD should be wired to the PTC320 in one of the following two ways(assuming
the leads are white and black):
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Option 1
White
White
Unconnected
Black
Black
Option 2
Black
Black
Unconnected
White
White
RTDs with two wires can bemodified by connecting two additional wires, one oneach side of
the sensing element and as close to the sensingelement as possible.
The higher the resistance of a sensor, the more its leads pickup noise from ambient
electromagnetic radiation. The noise level of high-resistancethermistors in particular can often be
improved by using a shielded cable and connecting the shield to pin 3.
Excitation current
The excitation current provided to the sensoris automaticallydetermined by thePTC320. For
resistive sensors, the current is determined by the type of sensor and the measurement range as
shown in the table below. When a diodesensor is in use, the card always produces a 10 µA
excitation.
Measurement
range
RTD
excitation
Therm istor
excitation
Diode
excitation
30
5 mA
200 µA
100
2 mA
100 µA
300
1 mA
50 µA
1 k
500 µA
30 µA
3 k
200 µA
20 µA
10 k
100 µA
10 µA
30 k
50 µA
5 µA
100 k
10 µA
3 µA
300
5 µA
2 µA
2.5 V ( )
1 µA
1 µA
10 µA
Excitation current produced by the PTC320
The thermistor excitation current results in about 1 µW of power being dissipated in the
thermistor at the high end ofeach measurement range. Therefore, if the dissipation constant of the
thermistor is above 1 mW/°C, the measurement error due to self-heating should be less than 1
mK.