Video Demo


• Temperature control from 100°C to 1210°C

• Two models to choose from: Reference (ADT878) and Standard (ADT875)

• Display Accuracy of ±1.5°C (ADT878)

• 4 on-board measurement channels (PC option)

• Process calibrator option provides a multi-channel readout for TCs, switches and transmitters, including task documentation and HART communication

• Portable, rugged and quick to temperature

• Self-calibration feature (PC option)

• Multi-zone temperature control

• Internal and external sensor control (PC option)

• Metallic interchangeable inserts

• Wi-Fi and Bluetooth capable

• Color touch screen display

• ISO 17025-accredited calibration w/data included

• Patent pending technology

We understand the many challenges associated with thermocouple calibration work. That is precisely why we decided to introduce the ADT875-1210 and ADT878-1210 Thermocouple Calibration Furnaces. 


With an unmatched stability, uniformity and an optional on-board process calibrator, calibrating thermocouples has never been easier. With two separate units to choose from, the ADT875-1210 and ADT878-1210 furnaces include a patented multi-zone temperature control which provides a never before seen, highly stable and uniform heat source to ensure you get the best possible results from a modest investment. With metallic interchangeable inserts, users have the flexibility needed to service a wide variety of UUT’s and the durability they have come to expect from Additel. The ADT875-1210 and ADT878-1210 can be purchased with or without our on-board process calibration electronics to provide flexibility for customers who are needing the best 1200°C heat source on the market. 


If thermocouple calibration and/or verification work is part of your workload, you don’t want to miss out on this opportunity to save valuable time and money with these best in class furnaces from Additel. 


Temperature Control 


The Additel ADT875 and ADT878 Thermocouple Calibration Furnaces have been designed with a unique and innovative way of controlling temperature and temperature gradients. We like to call it “Advanced Adaptive Control”. This exciting new design feature incorporates our patent pending wind tunnel control technology with Additel’s impressive 3-zone temperature control to provide the very best uniformity and stability possible.  


Each ADT875 and ADT878 is tested and calibrated in Additel’s accredited laboratory (Brea, CA) to ensure that each unit is ready to go when the customer opens the package. The included accredited calibration certificate provides data relating to accuracy, stability and uniformity to help provide even more confidence in the testing and calibration of each and every ADT875 and ADT878 Thermocouple Calibration Furnace. 


Process Electronics  


Both the ADT875 and ADT878 can be ordered with Additel's Process Calibrator(PC) option. The Process Calibrator Option combines the many features foundin a thermocouple readout device and process calibrator with the ADT875 andADT878 Calibration Furnaces.This unique option includes Additel’s patented Quick-Push connectors which accommodate virtually all TC connection types. The Process option also includes the ability to measure a reference grade thermocouple and up to (4) under test channels. Channels 1 and 2 can measure mA, voltage, perform switch testing and source 24V DC. In addition to these measurement functions, the process option provides full documenting capability of creating tasks, saving"as found" and "as left" results and HART communications for simplified transmitter work. The snapshot feature allows users to capture all information displayed on the screen with a touch of the screen. This optional add-on allows for data logging of all channels using our auto step and a ramp functions. By utilizing the external reference option users can select to control to the furnace set point using an external control probe, which helps to reduce uncertainties. The external control probe feature also facilitates the handy self-calibration feature! 


• Thermocouple Calibration

• Temperature Transmitter Calibration

• Annealing / Heat Treating

• High Temperature PRT Calibration

• Industrial Temperature Sensor Verification


General Specifications
Temperature Range100°C to 1210°C
Display Accuracy±1.2°C @ 100°C±1.0°C @ 100°C
±1.2°C @ 300°C±1.0°C @ 300°C
±1.2°C @ 600°C±1.0°C @ 600°C
±1.6°C @ 900°C±1.2°C @ 900°C
±2.0°C @ 1210°C±1.5°C @ 1210°C
Axial Uniformity (20mm zone)±0.6°C @ 100°C±0.4°C @ 100°C
±1.2°C @ 300°C±0.8°C @ 300°C
±1.5°C @ 600°C±1°C @ 600°C
±1.5°C @ 900°C±1°C @ 900°C
±1.5°C @ 1210°C±1°C @ 1210°C
Radial Uniformity±0.2°C @ 100°C±0.2°C @ 100°C
±0.3°C @ 300°C±0.3°C @ 300°C
±0.4°C @ 600°C±0.4°C @ 600°C
±0.8°C @ 900°C±0.6C @ 900°C
±1°C @ 1210°C±0.8°C @ 1210°C
Loading Effect±0.5°C
Environmental Conditions8°C to 38°C guaranteed accuracy
0°C to 50°C, 0% to 90% RH non-condensing,
3000 M altitude for normal operation
Storage Conditions-20°C to 60°C
Immersion DepthXR style inserts = 138 mm (5.43")
XS style inserts = 116 mm (4.57")
(see insert ordering info for more details)
Insert Size - OD24.8 mm (0.98 inches)
Heating Time50 min: 23°C to 1210°C
Cooling Time50 mins:1210°C to 300°C 50 mins: 300°C to 50°C55 mins:1210°C to 300°C 55 mins: 300°C to 50°C
Typical Time to Stability15 min
Units°C, °F, and K
Display6.5 in (165 mm) color touch screen
Size (H x W x D)345 x 170 x 330 mm (13.6 x 6.7 x 13.0 in)
Weight10.6 kg (23.4 lbs)
Power Requirements115 V AC (±10%) or 230 V AC (±10%), switchable, 45-65 Hz, 580 W
Mechanical TestingVibrat ion: 2 g (10-500 Hz) , 30 min for 2 sides
Impact: 4 g three times
Drop test: 500 mm (19.6 in)
CommunicationUSB A, USB B, RJ45, WiFi, Bluetooth
LocalizationEnglish, Chinese, Japanese, Russian, German
Warranty1 year
[1] 878-1210 specifications require use of an "XR" style insert. Otherwise, default to the 875-1210 specifications.
Input Specifications (Process Calibrator [PC] Option)
TC Measurement ChannelsPatented TC terminals: Accepting S, R, K, B, N, E, J, T, L, and U
TC Measurement Accuracy Type K Ch. 1-4 (excluding sensor)±0.182°C @ 100°C±0.172°C @ 100°C
±0.266°C @ 300°C±0.236°C @ 300°C
±0.310°C @ 600°C±0.251°C @ 600°C
±0.397°C @ 900°C±0.304°C @ 900°C
±0.517°C @1210°C±0.382°C @ 1210°C
TC Range–75 mV to 75 mV (UUT Channels 1-4)
–18 mV to 18 mV (Reference Channel)
TC Resolution0.0001 mV, Input Impedance < 10Ω
TC Voltage Accuracy0.02% RD + 8μV (ch. 1-4)0.01% RD + 8μV (ch. 1-4)
0.01% RD + 2μV (ref ch.)0.005% RD + 2μV (Ref ch.)
Internal CJC Accuracy±0.35°C (ch. 1-4)±0.30°C (ch. 1-4)
±0.25°C (ref ch.)±0.20°C (ref ch.)
Current Range–30 mA to 30 mA
Current Accuracy±(0.02% of rdg+ 2μA)±(0.01% of rdg + 2μA)
Current Resolution0.0001 mA
Voltage Ranges–12 V to 12 V and –30 V to 30 V
Voltage Accuracy±(0.02% of rdg+ 2mV)±(0.01% of rdg+ 0.6mV)
Voltage Resolution0.0001 V, Input Impedance >1MΩ
DC 24V Output24 V ± 10%, MAX 60 mA
Hart CommunicationOptional (ADT875PC and ADT878PC Models)
Temperature Coefficient 0°C to 8°C and 38°C to 50°CTC Readouts: ±5 ppm/°C
Current: ±5 ppm/°C
Voltage: ±5 ppm/°C
Switch TestMechanical or Electrical - Channels 1 & 2 only
DocumentationUp to 1,000 tasks which store up to 10 results each containing as found and as left data. Snap shot feature allows for screen captures. Records auto step and ramp functions
TC Measurement Specifications
TC TypeTEMP (°C)Error (°C)[1]
K (CH1-CH4)100±0.182±0.172
N (CH1- CH4)100±0.273±0.264
E (CH1- CH4)100±0.136±0.126
L (CH1- CH4)100±0.223±0.214
U (CH1- CH4)100±0.270±0.261
J (CH1- CH4)100±0.186±0.177
S (CH1-CH4)100±1.102±1.094
R (CH1- CH4)100±1.080±1.072
B (CH1- CH4)250±3.182±3.170
T (CH1- CH4)100±0.194±0.185
S (EXT. REF)100±0.277±0.273
R (EXT. REF)100±0.271±0.266


File nameUpload DateSize
Additel 875-1210 and 878-1210 Dry Well Calibrator Datasheet 2020.5.14 1 MB
Additel 875-1210 and 878-1210 Dry Well Calibrator User Manual 2020.11.17 1.4 MB

Update Packages:

File name Upload Date Size
Additel 875-1210 and 878-1210 Firmware Package 2021.1.13 11.6 MB
HART Temperature Library Update Package 2019.6.5 50.7 MB
HART Pressure Library Update Package 2019.6.5 138.4 MB