PPMS Hall measurement package comparison

Use the guarded insert alone or with the high-resistance Hall measurement package.

	High resistance up to 200 GΩ	Standard resistance up to 10 MΩ

Benefits	Benefits with M91 + Lake Shore guarded insert: Fastest measurements with reduced settling times Best performance for low-noise, low-current measurements Fully guarded from instrument to sample	Benefits with M91 integration: Cut measurement time up to one-half with no field reversal needed Switching technique minimizes thermal drift Eliminates manual trial-and-error steps with optimized calculations
Resistance range	10 mΩ to 200 GΩ	10 mΩ to 10 MΩ
Integration	M91/PPMS integration with low noise, fully guarded insert	M91/PPMS integration with breakout box
FastHall model	M91-HR (high resistance)	M91 (standard)
FastHall excitation	Current source, voltage source	Current source
Sample mounting	Lake Shore sample board	PPMS sample puck
Signal path	Fully guarded (internal coaxial) from instrument to sample	Standard twisted pair wiring
Mobility	10⁶ cm²/(V s) to 0.001 cm²/(V s)
Sample types	Supports van der Pauw and Hall bar samples
Temperature sensor	Integrated Cernox® temperature sensor local to sample
Control software	FastHall’s MeasureLINK® software for Hall measurement control integrates easily with the PPMS MultiVu™ application software

High-resistance package — PPMS/M91 integration via Lake Shore guarded insert

PPMS Hall connection kit 2

Diagram 1: PPMS connected to the M91 with the guarded insert

Features

Fully guarded from instrument to sample for ultra-low noise measurements
M91-HR resistance measurements up to 200 GΩ
Samples mount to consumable Lake Shore sample carrier boards (also pin compatible with Quantum Design sample carrier boards); 12 are included

Specifications summary

Pin-to-pin leakage current (base temp)	50 fA
Pin-to-insert body leakage current (base temp)	50 fA
Max current per pin	100 mA
Max voltage between any 2 pins and insert body	50 V
Operating temperature range	1.9 K to 400 K

Sample connections

Diagram 1 generally shows how the PPMS/M91 connection is made via the Lake Shore guarded insert (Diagram 2).

The M91 supports both van der Pauw (4-connection) and Hall bar (6-connection) geometries. These samples are wired to the Lake Shore sample board (Diagram 3). The sample board then snaps into the sample insert board located on the probe (Diagram 4).

When the guarded insert is loaded into the PPMS, these sample connections are fully guarded up to the M91 via triaxial cables (included in kit). The integrated Cernox® sensor connections go to the PPMS, enabling temperature readings directly through MultiVu. Diagram 5 shows a close-up view at the working end of the insert.

Guarded insert for PPMS

Diagram 2: Lake Shore guarded insert

Diagram 3: Sample carrier board

Diagram 4: Sample mount board

Hall insert sample connections

Diagram 5: Guarded insert connections

Standard resistance package — PPMS/M91 integration via Lake Shore breakout box

PPMS Hall connection kit 1

Diagram 6: PPMS connected to the M91 via breakout box

Features

Compatible with the Quantum Design PPMS puck
M91 resistance measurements up to 10 MΩ

Sample connections

The M91 supports both van der Pauw (4 connections) and Hall bar (6 connections) geometries. These samples should be wired to Quantum Design’s PPMS sample puck as shown in Diagram 2. When inserted into the PPMS, these sample connections are present on the LEMO connector on the side of the PPMS. The M91‑TRIAX‑DB25 breakout box enables these pins to connect to the M91. Six triaxial cables are included in the kit. Note: guarding is only up to the breakout box.

Gray LEMO (puck) pins	FastHall triaxial
3 (CH 1, I+)	1
7 (CH 2, I+)	2
8 (CH 2, I-)	3
12 (CH 3, I-)	4
4 (CH 1, I-)	5
11 (CH 3, I+)	6
10 (CH 2, V-)	AUX 1
9 (CH 2, V+)	AUX 2
6 (CH 1, V-)	Measure common

Note: Internal jumper on measure common: Gray LEMO pin 6, puck CH 1, V-; P1-user bridge D shield, pin 13

Diagram 7: Pinning for PPMS sample puck