Introduction

Battery temperature measurement is essential for evaluating safety, longevity, and performance in modern testing environments. Arbin supports three primary sensor technologies—thermocouples (Type T and K), RTDs (PT100), and thermistors (10kΩ)—each available through dedicated auxiliary input modules. These sensors enable precise temperature control, monitoring, and safety logic throughout battery R&D and production

Description

Battery testing requires pushing cells to their limits to evaluate durability, safety, and performance. Monitoring temperature helps prevent early degradation and avoid dangerous outcomes such as thermal runaway or fire. This document outlines the three primary sensor technologies used for battery temperature measurement—thermocouple, RTD, and thermistor—and details how Arbin supports each through dedicated input modules.

Overview of Arbin’s Auxiliary Temperature Input Modules

Arbin’s auxiliary temperature modules provide accurate and flexible thermal monitoring across a wide range of battery testing applications. Supporting four sensor types—PT100 RTD, PT10k thermistor, T-type thermocouple, and K-type thermocouple—each module allows users to select the best match for their test environment based on desired temperature range, accuracy, and response time.

All modules include 16 input channels and integrate with Arbin’s MITS software for real-time data logging, safety interlocks, and temperature-based test control. Channels may be mapped one-to-one or one-to-many with DC channels to enable cell-level or chamber-level monitoring.

• PT100 RTD Module: Offers the highest precision (±0.1°C) and long-term stability, ideal for applications requiring accurate surface temperature readings or formation control. Utilizes a 4-wire input to minimize electrical noise.
• PT10k Thermistor Module: Provides fast response and fine sensitivity over a moderate temperature range, well-suited for compact setups or direct cell surface monitoring. Features a simplified 2-wire input.
• T-Type Thermocouple Module: Best suited for low-temperature and cryogenic environments, offering stable performance down to –200°C. A reliable choice for lithium battery testing in cold climates or refrigerated chambers.
• K-Type Thermocouple Module: Designed for high-temperature applications up to 1,200°C, such as elevated-stress or abuse testing, while maintaining strong durability and responsiveness.

Whether monitoring cells, test chambers, or safety-critical conditions, Arbin’s modules deliver the flexibility and accuracy required for advanced R&D and production validation workflows.

Specifications

Sensor type	Thermocouple	RTD (PT100)	Thermistor (10kΩ)
Temp Range (typical)	−200 to 1,750°C	−200 to 650°C	−100 to 325°C
Accuracy (typical)	0.5 to 5°C	0.1 to 1°C	0.05 to 1.5°C
Long-term stability @ 100°C	Variable	0.05°C/year	0.2°C/year
Linearity	Non-linear	Fairly linear	Exponential
Power required	Self-powered	Constant voltage or current	Constant voltage or current
Response time	Fast  (0.10 to 10 s)	Slow  (1 to 50 s)	Fast  (0.12 to 10 s)
Susceptibility to electrical noise	Susceptible / Cold junction compensation	Rarely susceptible	Rarely susceptible   High resistance only

Thermocouple

A thermocouple consists of two dissimilar metal wires joined at one end, generating a voltage that corresponds to the temperature at the junction. Common types for battery testing include K, J, T, E, and N, while types R, S, C, D, and B are used for higher-temperature applications. 

Arbin supports T, K, J, and E thermocouples, with T and K types being standard and fully supported by default.

When selecting a thermocouple, the following considerations are important (adapted from OMEGA guidelines): 

• Determine the application environment.
• Identify the minimum and maximum temperatures the thermocouple will encounter.
• Consider chemical resistance for the sheath and junction.
• Evaluate abrasion and vibration resistance requirements.
• Account for specific installation or routing constraints.

Arbin supplies beaded wire thermocouples, consisting of two wires joined by a welded bead. This configuration allows for fast response times due to its minimal thermal mass. Beaded types are cost-effective, durable, and commonly used in battery testing. 

Each Arbin thermocouple input module includes 16 independent channels and integrates with MITS software for real-time temperature monitoring, control logic, and data logging. The module’s supported range (e.g., –270°C to 400°C for T-type) typically exceeds that of the sensor itself, though effective range depends on insulation materials and sensor construction.

Type-T Thermocouple 

The type-T thermocouple is composed of Copper/Constantan and is very stable even in low temperatures such as cryogenics.

Type T Sensors Range and Accuracy:  

The thermocouple sensor model is: 5SRTC-TT-T  

• The thermocouple is OMEGA, and the cable is PFA insulated wire
• The measuring range of the thermocouple probe: −200~350°C 
• Maximum operating temperature of PFA insulated wire of thermocouple: 150°C
• Thermocouple measurement accuracy:  

Standard error limit1:  

• 0~350°C, 1.0°C or 0.75%2  
• −200~0°C, 1.0°C or 1.5%  

Special error limit1, 2: 0~350°C, 0.5°C or 0.4% 

Arbin Type-T Temperature Input modules:  

• The board can support the measurement range greater than sensor limits: −270~400°C  
• Sampling speed: 0.8s   
• Measurement accuracy: ±1°C

1. Our current standard configuration is thermocouple with standard error limit. If customers need thermocouple with special error limit, our sales staff need to point out when placing an order. We need to purchase from the manufacturer, and the manufacturer will charge an additional 20%.
2. 0.75% means that the error is 0.75% of the current measured temperature reading.
   

K-Type Thermocouple

The Type-K thermocouple is composed of Nickle-Chromium/Nickle-Alumel and is the most common type of thermocouple. Type K thermocouples are inexpensive, reliable, and offer a wide temperature range with good accuracy.    

Type K Sensors Range and Accuracy:  

The thermocouple sensor model is: 5SRTC-TT-K

• The thermocouple is made by OMEGA, and the cable is PFA insulated.
• The measuring range of the thermocouple probe: −200~1,250°C.
• Maximum operating temperature of PFA insulated wire of thermocouple: 260°C.
• Thermocouple measurement accuracy:  

Standard error limit1:

• 0~1,250°C, 2.2℃ or 0.75%2
• −200~0°C, 2.2℃ or 0.75%  

Special error limit1, 2: 0~1,250°C, 1.1°C or 0.4%   

Arbin Type-K Temperature Input modules:  

• The board can support the measurement range greater than sensor limits: −270~1,370°C
• Sampling speed: 0.8s 
• Measurement accuracy: ±1°C 

1. Our current standard configuration is thermocouple with standard error limit. If customers need thermocouple with special error limit, our sales staff need to point out when placing an order. We need to purchase from the manufacturer, and the manufacturer will charge an additional 20%.
2. 0.75% means that the error is 0.75% of the current measured temperature reading.

RTD (PT100 Sensor)

A resistance temperature detector (RTD) is a sensor that measures temperature by correlating the resistance of a metal element with temperature. They have been a standard in laboratory testing for many years and have gained a solid reputation. Compared to thermocouples and thermistors, RTDs offer superior stability, accuracy, and long-term reliability. The majority of RTD elements are composed of a fine coiled wire wrapped around a sheath housing glass or ceramic. The materials used in the temperature sensor have predictable resistance changes that correlate with temperature.

Figure 1: The above PT100 sensors are our standard sensors

Arbin’s RTD module (PN 462558) uses a 4-wire PT100 configuration to minimize measurement noise and enhance accuracy. This module supports a temperature range of –50°C to 200°C with ±0.1°C module-level accuracy, and includes 16 input channels.

Arbin provides flat-profile, thin-film PT100 sensors composed of a ceramic substrate embedded with a platinum layer. This compact design enables fast and accurate sensing. 

RTD Sensors Range and Accuracy:  

• Manufacturer: Maserac Electronics  
• Grade A  
• Measuring range: −50~200°C 
• Measurement accuracy: ±(0.15+0.002×|t|)°C   
• (|t| refers to the absolute value of the current temperature)

Arbin RTD (PT100) Temperature Input modules:  

• The board can support the measurement range greater than sensor limits: −80~500°C 
• Sampling speed: 4.8ms  
• Measurement accuracy: ±0.1°C  

NOTE: PT100 sensors are required when used with Arbin’s MZTC Multi-Chamber. Cables will connect from Arbin’s thermistor input module to an interface on front of MZTC. Short (~6 inch) sensors are then provided inside each mini-chamber to place on cell for direct temperature measurement.

Thermistor (10k) Ω

Thermistors are temperature sensors made from ceramic or polymer-based materials. Unlike RTDs, which use metal elements, thermistors exhibit larger resistance changes in response to temperature, offering high sensitivity. The thermistor’s sensor is made up of a sintered semiconductor material which correlates large resistance changes to small temperature changes. A unique feature is the negative temperature coefficient which means resistance decreases with increasing temperature. Thermistors are made by combining metals and metal oxide materials which are then formed a fired into the required shape. Thermistors offer high resolution, fast response time, and good repeatability. Their small size makes them ideal for direct surface measurements where thermal gradients are important.  

Figure 2: The above 10kΩ thermistor sensors are our standard sensors. If customers have special requirements, we can select sensors that meet customer requirements.  

10kΩ Thermistor Sensors Range and Accuracy:  

• Manufacturer: Omega Precision Thermistor Resistance
• Measuring range: −80~120°C  
• Accuracy range:   

Temperature Range	Measurement Accuracy
−80 to −40°C	±1°C
−40 to 0°C	±0.4°C
0 to 70°C	±0.2°C
70 to 100°C	±0.3°C
100 to 120°C	±1°C

Arbin PT10kΩ Thermistor Input modules:  

Arbin supports 10kΩ NTC thermistors (e.g., Omega 44006 type) via its 16-channel thermistor input module (PN 462560). The module range is –80°C to 150°C with ±0.2°C accuracy. Thermistors provide fast response and are ideal for cell surface monitoring.

• The board can support the measurement range greater than sensor limits: −80~150°C  
• Sampling speed: 9.6ms  
• Measurement accuracy: ±0.2°C 
  

Max Operating Temperature: 1 second in well stirred oil, 10 seconds in still air. Time constant is the time required for a thermistor to indicate 63% of a newly impressed temperature.  

Dissipation Constant, Min: 8mW/C in well stirred oil, 1mW/C in still air. Dissipation constant is the power in milliwatts to raise a thermistor one degree C above surrounding temperature.  Tolerance Curves: The following curves indicate conformance to standard resistance temperature values as a % of resistance, and as a maximum interchangeability error expressed as temperature.   

Note: Arbin’s 10kΩ NTC thermistor module is compatible with standard Omega 44006-type thermistors.

Application Example

The example below introduces how temperature can be implemented as a safety setting in the MITS Pro Software. The user can define the maximum and minimum value allowed during the experiment. Temperature values can also be used within individual steps for step transitions or stopping the experiment.