Specifications

Specifications

Measurement type

AC, 4-lead differential, resistance

Number of inputs

1; up to 16 with scanner

Measurement units

Ω, K (with temperature response curve)

Resistance ranges

2 mΩ to 2 MΩ (excitation dependent)

Reading rate

10 readings per s (same range and channel)

Range change settling

3 s + filter settling

Channel change (scan) settling

3 s + filter settling

A/D resolution

24-bit

Input noise figure (370/3716)

33 nV/vHz

Input noise figure (3716L)

4 nV/vHz

Input noise figure (3708)

2 nV/vHz

Measurement resolution

Range dependent, (see 370 performance specification table)

Accuracy

Range dependent, (see 370 performance specification table)

Measurement temp coefficient

(±0.0015% of reading ±0.0002% of range)/°C

Lead connections

V+, V-, l+, l-, V shield, l shield, individual guards

Scanner lead connections

V+, V-, l+, l- for each sensor, shield common to all

Max lead resistance

100 Ω + 10% of resistance range per lead for current = 3.16 mA, 10 Ω + 10% of resistance range per lead for current = 10 mA

Input isolation

Measurement optically isolated from chassis ground

Common mode reduction

Matched impedance voltage input and current output, active CMR

Excitation type

Sinusoidal AC current source

Excitation frequency

13.7 Hz (9.8 Hz and 16.2 Hz alternates)

Excitation currents

21 ranges from 3.16 pA to 31.6 mA RMS

Minimum excitation power

10^-18 W into 100 kΩ (see 370 performance specification table)

Max DC current (370/3716)

4 pA + 1% of excitation current (1.6 × 10^-18 W into 100 kΩ)

Max DC current (3716L)

30 pA + 1% of excitation current

Current protection

Current leads relay shorted on power-up and range change

Voltage ranges

12 ranges from 2 µV to 632 mV RMS

Voltage over range

20% nominal

Input impedance

Approaches 5 × 10¹² Ω

Range selection modes

Manual, Voltage Excitation, Current Excitation, and Autorange

Scanner modes

Manual or Autoscan

Filter

Settling times 1 s to 200 s

Additional software features

Max/Min capture, Linear equation, user programmable pause on range and input change

Temperature conversion

Supported cryogenic temperature sensors

Any resistive sensor including NTC resistors (e.g., Germanium, Carbon-Glass, Cernox™, Ruthenium Oxide [Rox™]) and PTC resistors (e.g., Rhodium-Iron RTD)

Requirements

Requires calibrated sensor and a temperature response curve loaded into the instrument at Lake Shore or by the user

Temperature coefficient

Negative or positive

Temperature units

Low temperature

Below 20 mK in a well-designed system

Temperature resolution

Sensor and temperature dependent (see sensor performance)

Curve memory

Space for twenty 200-point curves

Curve entry

Entered via front panel, computer interface, or CalCurve™ option

Curve format

Ω/K, Log Ω/K

Temperature control

Control type

High resolution digital PID

Control modes

Closed Loop PID, Open Loop

Tuning modes

Manual PID, Zones

Setpoint units

Ω or K (with temperature calibration curve)

Setpoint resolution

Same as reading display resolution

Control stability

Below 10 mK p-p at 50 mK, system dependent

Heater output type

Variable DC current source

Heater output isolation

Optically isolated from chassis and measurement ground

Output D/A resolution

18-bit

Heater output ranges

100 mA, 31.6 mA, 10 mA, 3.16 µA, 1 µA, 316 µA, 100 µA , 31.6 µA

Heater output compliance

10 V

Max power of output ranges

1 W, 100 mW, 10 mW, 1 mW, 100 µW, 10 µW, 1 µW, 0.1 µW (nominal 100 Ω)

Heater type

Resistive

Heater resistance range

1 Ω to 100 kΩ, 100 Ω for maximum power

Heater output gain accuracy

±1% of setting

Heater output offset (at 0%)

±0.02% of range

Max heater noise current

<0.005% of range

PID Control Parameters

Proportional	0.001 to 1000
Integral	0 s to 10,000 s
Derivative	0 s to 10,000 s
Manual Output	0% to 100% (resolution 0.001%)

PID zone settings

10 zones that include setpoint, heater range, PID, relays, and analog outputs (still)

Still output

Up to 1 W of power available using analog output 2

Heater protection

Short circuit-protected, disabled with a relay on power-up, defaults to off range on power-up, selectable heater range limit, open circuit detection

Scanner support

Control with scanned input is supported with reduced stability

Front panel

Display type

Graphic (8 line by 40 character) vacuum fluorescent display

Number of reading displays

1 to 8

Reading display units

mΩ, Ω, kΩ, MΩ, mK, K

Display resolution

4, 5, or 6 digit, user selected

Display update rate

2 readings per second

Reading display options

Ω, K, Max, Min, Linear

Other displays

Channel number, units, resistance range, excitation voltage or current, excitation power, control setpoint, heater range, and heater output

Display annunciators

Reading errors, CMR, Alarm, Ramp, Zone, Remote

LED annunciators

Autorange, Excitation Mode, Autoscan

Keypad

36 key, numeric and specific functions

Interface

IEEE-488.2 interface capability

SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT0, C0, E1

Software support

LabVIEW™ driver for IEEE-488 interface (consult Lake Shore for availability)

Serial interface capability

RS-232C, DE-9 connector, 9600 baud

Alarms

Number	Up to 32, high and low for each channel
Settings	Source, High Setpoint, Low Setpoint, Deadband, Latching/Non-latching, Audible on/off
Actuators	Display annunciator, beeper, relays

Relays

Number	2
Contacts	Normally Open, Normally Closed, and Common
Contact rating	30 VDC at 5 A
Operation	Relays may be activated on high/low alarm setpoints or manually
Connector	Detachable terminal block

Analog voltage outputs

Number	2
Type	Variable DC voltage source
Scale	User specified
Range	±10 V
Resolution	0.3 mV, 0.003% of full scale
Accuracy	±2.5 mV
Maximum current	100 mA
Maximum power	1 W
Minimum load resistance	100 Ω (short circuit-protected)
Ground reference	Chassis
Operation	Tracks reading, error (DR) using linear equation, or use as still heater
Connector	BNC