TEC Microsystems - Miniature Thermoelectric Coolers and Sub-Assemblies

ISO9001:2015 Certified

DX4085 Z-METER Tester - Intro

DX4085 Z-Meter Tester is a portable measuring device for thermoelectric coolers express analysis. The device measures directly three key parameters (AC Resistance, Figure-of-Merit and Time Constant) of separate or integrated (mounted)  thermoelectric coolers. DX4085 has 2.4" LCD screen, built-in Li-Ion battery for up to 8 hours operating, it is autonomous and doesn't require a constant connection to PC. All necessary settings, measuring process results and history are displayed and adjusted on LCD screen. DX4085 is supported by standard Z-Meter software, and in case of a connection to PC you get additional functionality with precise corrections setup, TEC geometry settings and results export. The device has a miniature, pocket size form-factor and it's ideal for engineers and researchers dealing with TECs every day.


Connection to PC

Not obligatory. Stand-alone

PC Connection Interface

USB type A (cable is included)

Z-Meter Software

Included. Windows version only

Measurement Interface

External only (Clips on a cable, included)

Measurement Scheme

4-wires method

Ambient Temp. Sensor

Available, external

TEC Polarity Check


Typical TEC Testing Time


20 .. 180 (depending on TEC size and Time Constant)

Operating Conditions

Ambient Temperature


15 .. 35



0 .. 95

TEC AC Resistance Measurements ( ACR )



0.1 .. 100



0.6 (but >0.01Ohm)




Figure-of-Merit Measurements ( Z )



1 .. 4







TEC Time Constant



1 .. 100







TEC Operating Voltage measuring (DC)

Voltage Range


-20 … 20




External Temperature Sensor

Temperature Range


-40 … +85



± 0.25 (typical)

± 1 (maximum)

± 0.05 (typical) lifetime drift




DX4085 Power Supply

Built-in Li-Ion Battery 


2050 (up to 8 hours of operating)




Dimensions and Weight



70 x 160 x 21




- Express TEC parameters testing (ACR, Z, t)

- External temperature sensor

- External 4-wires measurement clips

- Suitable for separate and mounted TECs

- Acceptable for any TEC size

- 2.4" LCD for information output

- Stand-alone (no PC connection required)

- Compact "pocket-size" form-factor

  DX4085 Z-Meter Tester  Features

  DX4085 Manuals

Main Mode - measurement of three  TEC key  parameters (Figure-of-Merit, AC Resistance, Time Constant), ambient temperate is measured (when external temperature sensor is connected).

Additional Mode – measurement  of TEC AC Resistance only (express testing). Optimal mode for quick thermoelectric cooler check on "before-after basis".

Operating Mode – measurements of TEC parameters in operating mode – TEC operating voltage and/or TEC temperature check with external sensor is placed on TEC cold side.

PC Mode. Working through a connection to PC with Z-Meter Software (provided with the device). Extra options for measurements are available with TEC databases, precise corrections estimations and measurement results export.

DX4085 Operating modes

DX4085 combines a functionality of three devices in one - portable Z-Meter (ACR, Z, Time Constant ), voltmeter (to check exact TEC operating voltage) and digital thermometer (checking ambient temperature or TEC cold/hot sides temperature). Additionally there is an advanced PC mode, when DX4085 is connected to PC by USB cable.

DX4085 - Z-Meter Tester - for thermoelectric coolers express quality control

How does it work

DX4085 is a stand-alone device for express test of separate and integrated thermoelectric coolers.  DX4085 TEC Tester is the only device in Z-Meters family with no connection to PC required.  You may use it in the same easy way as a typical multimeter.  It's easy, convenient and quick to arrange TEC measurements with DX4085.  

Z-Meters use the Harman method in the measuring process. The setup is simple. You switchb on DX4085 attach the clips to TEC terminal wires and run the measurement process. TEC measurement process usually takes 20 to 180sec depending on measuring process parameters and TEC type.

If required you may connect DX4085 to PC and run using the standard Z-Meter software.  In this case some additinal features are available - measuring results saving on PC, default settings and precise modes with additional TEC measurement corrections included. The precise mode requires TEC construction parameters (detailed geometry and wires) to be configured in the software.

Measuring Process notes

Z-Meter DX4085 Tester uses  Harman method in measuring process.  The results are precise and accurate for the single-stage thermoelectric coolers, once such TECs are fully symmetrical.  Z-Meter can also calculate dTmax precisely for a single-stage TEC.  With multistage thermoelectric coolers Z-Meter has certain limitations, cause during measuring process in multistage TEC each stage starts to interfere with the next one.  The measuring results for single-stage thermoelectric cooler are absolute.  In case of multistage TEC only ACR resistance is the absolute value, while the rest measured parameters can be used only as relative, for before and after comparison.

Thermoelectric Coolers with WB pads and posts

The standard measuring interface of the DX4085 Z-Meter is optimal for thermoelectric coolers with terminal wires. TECs with WB pads and posts or special SMD TEC configurations require an additional measuring interface - WB Clips. Z-Meter WB Clips is an optional accessory with stainless steel fixtures, manufactured by request for a specific TEC size. The compact instrument with spring clip fixation has 4-wires measuring method probes that don't damage TEC WB pads during the measuring process. The clip has a terminal connector compatible with all Z-Meter versions. WB Clips are not included in the standard DX4085 set by default because there is no universal solution.  

WB Clips are not included in the DX4085 standard set, the clips are manufactured individually by request, following the particular thermoelectric cooler dimensions, WB pads or posts geometry and position.

TEC Measuring Process

With Z-Meter you can quickly test thermoelectric cooler parameters and compare them with TEC manufacturer's batch specification. Thus the income TEC quality control (QC) becomes fast and easy with Z-Meter.  But the best way to use Z-Meter is the step-by-step control of TEC during your mounting procedures and integration into final assembly.  Thermoelectric coolers may pass through various processes with mechanical and thermal impacts during TEC integration into a final design.  Soldering, baking/annealing, mechanical pressure and shear forces, various thermal shocks and temperature cycling - after each stage it's better to check and control all TEC parameters and conditions to be sure that TEC is not damaged.

The testing can be done simply by ACR only or with full control of all three TEC key parameters. The accurate and precise control of TEC parameters based on "before-after" comparisons saves time and money. Any potential risk of TEC failure can be identified at early stage, so you can be sure that TEC is fully functional after all mounting processes and has can provide the required cooling performance.

Z-Meter helps to identify quickly the reasons of TEC failure in the final device.  You may quickly understand that TEC is mechanically damaged by ACR measuring, or identify TEC detachment inside a package by Time Constant parameter measurement.  Z-Meter is spoecially developed for thermoelectric coolers and gives considerably more possibilities with TEC quality control than any standard device like LC meters.

What you can see with Z-Meter

TEC AC Resistance (ACR), Figure-of-Merit (Z) and Time Constant give you excessive info about the thermoelectric cooler.  The measurement of these three parameters and the comparison based on the "before-after" method help to identify the most common reasons for TEC failure.  It's possible to idendify the mechanical damage of thermoelectric cooler, degradation of TEC BiTe material, poor integrating or detachment of TEC in a package.  The detailed review is available by this link.  

- No Connection to PC is required

- Can be connected to PC to get extra features

  DX4085 Requirements

Other Z-Meter devices available

There are several Z-Meter versions available, each one with some key features.  The measuring methodic and tolerances are the same for all Z-Meter devices.  The differences are in form-factor, usability, measuring interfaces and application scope.  Please, check the following devices available:

DX4190 - 10position Z-Meter for volume manufacturers

Z-Meter DX4190 is the must-have device for TEC manufacturers or consumers with serious TEC volumes. DX4190 provides 100% Quality Control for thermoelectric coolers in all stages of mass production with no compromises. The device  measures TEC key parameters  for up to 10 thermoelectric coolers simultaneously. DX4190 can be used with separate (not mounted) TECs by manufacturers or consumers at income/outcome control, or TECs quality control and performance testing in the end-product with thermoelectric cooler integrated.

DX4095 Mini - Z-Meter in USB-stick

Z-Meter Mini DX4095 is a portable TEC tester for thermoelectric coolers express analysis. The device has ultra-miniature, pocket size form-factor and it's ideal for engineers and researchers dealing with TECs. Due to a very small size DX4095 has only external measurement interface - external clips - connected to Z-Meter.  DX4095 has also a built-in temperature sensor for accurate TEC ACR calculations.  DX4095 is recommended for regular express quality control of small TEC batches, occasional QC testing, R&D analysis and TEC integrating/assembly process control and optimization.

DX4090 Z-Meter Classic

DX4090 device has two measurement interfaces - an internal chamber (works as a passive thermostat) with connectors and an external interface with clips. DX4090 has also a built-in temperature sensor for accurate TEC ACR calculations and a heating element for TEC quick polarity. DX4090 is recommended for regular express quality control of small and mid-size TEC batches, R&D analysis and TEC integrating/assembly process control and optimization.

DX4091 Pellet Tester

Z-Meter model DX4091 stays separate from the rest devices in our Z-Meter family. While the rest devices measure thermoelectric coolers as assembled units, DX4091 uses a unique and innovative methodic to test a single BiTe pellet (post). The compact table-top device measures  Resistance (R), Conductivity (σ) and Figure-of-Merit (Z) of a single BiTe pellet.  DX4091 is recommended mainly for thermoelectric modules manufacturers and R&D specialists interested in thermoelectric materials analysis and QC.















Pellet Tester