Specifications

 
Input specifications - click here for sample calculations of typical sensor performance
 
 Sensor temperature coefficient Input
range
Excitation
current
Display
resolution
Measurement
resolution
Electronic
accuracy offset
Electronic
control
stability11
Diode
340/3462
negative0 V to 2.5 V
10 µA
± 0.05%12, 13
10 µV10 µV±80 µV ±0.005% of rdg  20 µV
negative0 V to 7.5 V
10 µA
± 0.05%12, 13
10 µV10 µV±80 µV ±0.01% of rdg20 µV
PRC RTD
340/3462
positive0 Ω to 250 Ω1 mA141 mΩ1 mΩ±0.002 Ω ±0.01% of rdg 2 mΩ
positive0 Ω to 500 Ω1 mA141 mΩ1 mΩ±0.002 Ω ±0.01% of rdg2 mΩ
positive0 Ω to 2500 Ω0.1 mA1410 mΩ10 mΩ±0.03 Ω ±0.02% of rdg20 mΩ
NTC RTD
1 mV
340/3462
negative0 Ω to 10 Ω100 µA14100 µΩ1 mΩ±0.02% rng ±0.1% of rdg2 mΩ
negative0 Ω to 30 Ω30 µA14100 µΩ3 mΩ±0.02% rng ±0.1% of rdg6 mΩ
negative0 Ω to 100 Ω10 µA141 mΩ10 mΩ±0.02% rng ±0.1% of rdg20 mΩ
negative0 Ω to 300 Ω3 µA141 mΩ30 mΩ±0.02% rng ±0.1% of rdg60 mΩ
negative0 Ω to 1 k Ω1 µA1410 mΩ0.1 Ω±0.02% rng ±0.1% of rdg0.2 Ω
negative0 Ω to 3 k Ω300 nA1410 mΩ0.3 Ω±0.02% rng ±0.1% of rdg0.6 Ω
negative0 Ω to 10 k Ω100 nA140.1 Ω1 Ω±0.02% rng ±0.1% of rdg2 Ω
negative0 Ω to 30 k Ω30 nA140.1 Ω3 Ω±0.02% rng ±0.1% of rdg6 Ω
NTC RTD
10 mV
340/3462
negative0 Ω to 30 Ω300 µA14100 µΩ300 µΩ±0.02% rng ±0.05% of rdg600 µΩ
negative0 Ω to 100 Ω100 µA141 mΩ1 mΩ±0.02% rng ±0.05% of rdg2 mΩ
negative0 Ω to 300 Ω30 µA141 mΩ3 mΩ±0.02% rng ±0.05% of rdg6 mΩ
negative0 Ω to 1 kΩ10 µA1410 mΩ10 mΩ±0.02% rng ±0.05% of rdg20 mΩ
negative0 Ω to 3 kΩ3 µA1410 mΩ30 mΩ±0.02% rng ±0.05% of rdg60 mΩ
negative0 Ω to 10 kΩ1 µA140.1 Ω0.1 Ω±0.02% rng ±0.05% of rdg0.2 Ω
negative0 Ω to 30 kΩ300 nA140.1 Ω0.3 Ω±0.02% rng ±0.05% of rdg0.6 Ω
negative0 Ω to 100 kΩ100 nA141 Ω3 Ω±0.02% rng ±0.05% of rdg6 Ω
negative0 Ω to 300 kΩ30 nA141 Ω30 Ω±0.02% rng ±0.25% of rdg60 Ω
Thermocouple
3464
positive±25 mV NA0.1 µV0.2 µV±1 µV ±0.05% of rdg150.4 µV
positive±50 mV NA0.1 µV0.4 µV±1 µV ±0.05% of rdg150.8 µV
Capacitance
3465
positive or negative 0 nF to 150 nF
4.88 kHz
1 V square wave
10 pF2.0 pF±50 pF ±0.1% of rdg4.0 pF
positive or negative 0 nF to 15 nF
4.88 kHz
1 V square wave
1 pF0.2 pF±50 pF ±0.1% of rdg0.4 pF
Diode
3468
negative0 V to 2.5 V
10 µA
± 0.05%12, 13
100 µV20 µV±160 µV ±0.01% of rdg40 µV
negative0 V to 7.5 V
10 µA
± 0.05%12, 13
100 µV20 µV±160 µV ±0.02% of rdg40 µV
PTC RTD
3468
positive0 Ω to 250 Ω1 mA ± 0.3%1410 mΩ2 mΩ±0.004 Ω ±0.02% of rdg4 m Ω
positive0 Ω to 500 Ω1 mA ± 0.3%1410 mΩ2 mΩ±0.004 Ω ±0.02% of rdg4 m Ω
positive0 Ω to 5000 Ω1 mA ± 0.3%14100 mΩ20 mΩ±0.06 Ω ±0.04% of rdg40 m Ω
NTC RTD
3468
negative0 Ω to 7500 Ω10 µA ± 0.05%14100 mΩ50 mΩ±0.01 Ω ±0.04% of rdg0.1 Ω
11 Control stability of the electronics only, in an ideal thermal system
12 Current source error has negligible effect on measurement accuracy
13 Diode input excitation current can be set to 1 mA – refer to the Model 331 user manual for details
14 Current source error is removed during calibration
15 Accuracy specification does not include errors from room temperature compensation
Thermometry

Number of inputs

2 included (additional inputs optional)

Input configuration

Each input is factory configured as diode/RTD. Thermocouple and capacitance are optional and sold as additional input cards.

Isolation

Sensor inputs optically isolated from other circuits but not from each other

A/D resolution

24-bit analog-to-digital

Input accuracy

Sensor dependent – refer to Input Specifications table

Measurement resolution

Sensor dependent – refer to Input Specifications table

Maximum update rate

Up to 20 readings per s on an input, 40 readings per s on all inputs

Autorange

Automatically selects appropriate NTC RTD range

User curves

Forty 200-point CalCurves™, or user curves

SoftCal™

Improves accuracy of DT-470 diode or platinum RTD sensors
MathMaximum and minimum of input readings and linear equation

Filter

Averages input readings to quiet display, settable time constant
Control
 

Control loops

2

Control type

Closed-loop digital PID with manual heater power output, or open loop

Tuning

Autotune (one loop at a time), manual PID, zones

Control stability

Sensor dependent – to 2× measurement resolution (in an ideal thermal system)

PID control settings
   Proportional (gain) 0 to 1000 with 0.1 setting resolution
   Integral (reset) 1 to 1000 with 0.1 setting resolution
   Derivative (rate) 1 to 1000 s with 1 s resolution
   Manual output 0 to 100% with 0.01% setting resolution

Zone control

10 temperature zones with P, I, D, manual heater power out, and heater range

Setpoint ramping

0.1 K per min to 100 K per min

Safety limits

Setpoint limit, curve temp limits, heater output, slope limit, heater range limit, power up heater off, and short-circuit protection
Heater output
 
Loop 1
Loop 2
Heater output type
Variable DC current source
Variable DC voltage
Heater output D/A resolution
18-bit
14-bit
Max heater power
100 W
1 W
Max heater output current
2 A
0.1 A
Heater output complaince
50 V
10 V
Heater source impedance
NA
0.01 Ω
Heater output ranges
5 decade steps in power
1
Heater load type
Resistive
Resistive
Heater load range
10 Ω to 100 Ω recommended
100 Ω minimum
Heater load for max power
25 Ω
100 Ω
Heater noise (<1 kHz) RMS
50 µV + 0.001% of output voltage
<0.3 mV
Isolation
Optical isolation between output and other circuits
None
Heater connector
Dual banana
BNC
 
Loop 1 full scale heater power at typical resistance
Heater
resistance
Heater
range
Maximum current
2 A
1 A
0.5 A
0.25 A
10 Ω
5
40 W
10 W
2.5 W
625 mW
4
4 W
1 W
250 mW
62.5 mW
3
0.4 W
100 mW
25 mW
6.25 mW
2
40 mW
10 mW
2.5 mW
625 µW
1
4 mW
1 mW
250 µW
62.5 µW
25 Ω
5
100 W
25 W
6.25 W
1.56 W
4
10 W
2.5 W
625 mW
156 mW
3
1 W
250 mW
62.5 mW
15.6 mW
2
100 mW
25 mW
6.25 mW
1.56 mW
1
10 mW
2.5 mW
625 µW
156 µW
50 Ω
5
50 W
50 W
12.5 W
3.12 W
4
20 W
5 W
1.25 W
312 mW
3
2 W
500 mW
125 mW
31.2 mW
2
200 mW
50 mW
12.5 mW
3.12 mW
1
20 mW
5 mW
1.25 mW
312 µW


Extending temperature controller heater power
 
It is often necessary to extend the heater power of a cryogenic temperature controller to conduct experiments above room temperature. This diagram illustrates a practical way to increase the control output of the Model 340 to several hundred watts. A programming resistor, Rpgm, is placed across the controller’s heater output current source. As the heater output current changes, a changing voltage is generated across Rpgm. That voltage is used to program a large external power supply. Rpgm should be chosen so that a low current range of the controller can be used. The control output of loop 2 on the Model 340 is a voltage, thus it can be connected directly to the external power supply without Rpgm.
 

 

Sensor input configuration
 
 
Diode/RTD
Thermocouple
Capacitance
Measurement type
4-lead
differential
2-lead, room temperature compensated
4-lead
Excitation
Constant current with current reversal for RTDs
NA
4.88 kHz, 1 V square wave
Supported
sensors
Diodes: Silicon, GaAlAs
RTDs: 100 Ω Platinum, 1000 Ω Platinum, Germanium, Carbon-Glass, Cernox™, and Rox™
Most thermocouple types
CS-501GR
Standard
curves
DT-470, DT-500D, DT-670, PT-100, PT-1000, RX-102A,
RX-202A
Type E, Type K, Type T AuFe 0.07% vs. Cr, AuFe 0.03% vs Cr,
None
Input
connector
6-pin DIN
Ceramic isothermal block
6-pin DIN
 
Front Panel
 
Display
Graphic LCD with fluorescent backlight
No. of reading displays 
1 to 8
Display Units
 
Temperature in K, ºC, or sensor units
Temp display resolution 
0.0001 K below 10 K, 0.001 K above 10 K
Sensor units display resolution
Sensor dependent, to 6 digits
Setpoint setting resolution
Same as display resolution
(actual resolution in sensor dependent)
Heater output display
 
Numeric display in percent of full scale for power or current-bar graph display of heater output available
Heater output resolution
0.1% numeric or 2% graphical
Keypad
Numeric plus special function
Front panel
features
Front panel curve entry, display brightness control, and keypad lock-out
Interfaces
 
IEEE-488.2 interface
   FeaturesSH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT0, C0, E1
   Reading rate To 20 readings per s
   Software Support National instruments LabVIEW™ driver

Serial interface
   Electrical format RS-232C
   Max baud rate 19,200 baud
   ConnectorRJ-11
   Reading rate To 20 readings per s

Alarms
 
   Number Two, high and low, for each installed input
   Data source Temperature, Sensor Units, and Linear Equation
   SettingsSource, High and Low Setpoint , Latching or Non-latching, and Audible On/Off
   ActuatorsDisplay, annunciator, beeper, and relays

Relays
 
   Number 2
   Contacts Normally open (NO), normally closed (NC), and common (C)
   Contact rating 30 VDC at 2 A
   Operation Activate relays on high or low alarms for any input, or manual off/on
   ConnectorDetachable terminal block

Analog voltage outputs
(when not used as control loop 2 output)
 
   Number 2
   Scale User selected
   Update rate 20 readings per s
   Data source Temperature, Sensor Units, and Linear Equation
   Settings Input, Source, Top of Scale, Bottom of Scale, or Manual
   Range ±10 V
   Resolution 1.25 mV
   Accuracy±2.5 mV
   Max output power 1 W
   Min load resistance 100 Ω (short-circuit protected)
   Source impedance 0.01 Ω

Digital I/Ω

5 inputs and 5 outputs – TTL voltage level compatible

Data card

PC card Type II slot used for curve transfer, setup storage, and data-logging
General
 
Ambient temp range
20 °C to 30 °C (68 °F to 86 °F) for specified accuracy; 15 °C to 35 °C (59 °F to 95 °F) for reduced accuracy

Power requirements

100, 120, 220, 240 VAC (+5%, -10%), 50 or 60 Hz; 190 VA

Size

432 mm W × 89 mm H × 368 mm D (17 in × 3.5 in × 14.5 in), full rack

Weight

8 kg (17.6 lb) approx.

Approval

CE mark
 
3003 Heater output conditioner
 
The heater output conditioner is a passive filter which further reduces the already low Model 340 heater output noise. The typical insertion loss for the Model 3003 is 20 dB at or above line frequency, and >40 dB at or above double line frequency. A 144 mm W × 72 mm H × 165 mm D (5.7 in × 2.8 in × 6.5 in) panel mount enclosure houses this option, and it weighs 1.6 kg
(3.5 lb).
 

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