Temperature Calibration Equipment
01
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
Portable Calibration Bath
Additel 835
OVERVIEW
The ADT835 is a portable calibration bath with a compact bath size of 3.54 x 3.54 inches (90 x
90 mm), setting a new benchmark for powerful, space-saving calibration solutions. Unlike typical
integrated dry-liquid baths, the ADT835 delivers exceptional versatility—accommodating temperature
sensors of virtually any type, size, or shape. Its innovative design supports both batch and field
calibrations with ease, while maintaining excellent stability, uniformity, and accuracy. Combining the
precision and reliability of a traditional calibration bath with the portability of a dry well, the ADT835 is
a dependable choice for demanding calibration environments.
The ADT835 delivers exceptional performance through a smart, user-focused design. Its advanced
data logging capabilities simplify documentation and help minimize errors or missed readings. Built-in
application tools enhance workow efciency, while intelligent remote control functionality allows for
multitasking and increased productivity. The 6.5-inch TFT touchscreen provides an intuitive interface,
making operation straightforward—even for rst-time users.
Engineered for exceptional portability and performance
Extended temperature range: -30°C to 250°C
High-precision accuracy: ±0.1°C
Compatible with a wide range of probe types and sizes
Optional built-in Process Calibrator (PC)
Quick to temperature
Delivers outstanding stability and uniformity
Fast thermal response for efficient operation
Features advanced dual-zone heating technology
One touch self-calibration
Designed with robust electromagnetic interference protection
02
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Temperature Calibration Equipment
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
Versatile Sensor Calibration with the ADT835
Calibrating a wide range of temperature sensors is a challenge, particularly in industries
like pharmaceuticals, biotechnology, and food processing, where specialized or sanitary
sensors are common. These sensors often feature large anges, ferrule nuts, or short
probes, making on-site calibration with traditional dry wells difcult and costly. Users
may need to invest in custom dry wells, yet still face limitations in achieving accurate
results. The ADT835 portable calibration bath addresses these challenges by providing
a stable and uniform temperature eld, ensuring precise calibration for sensors of
various types, sizes, and shapes, without the need for custom solutions.
Enhanced Efciency for Batch Calibration
Maximizing calibration efciency directly reduces factory downtime. To facilitate
batch calibration, portable temperature sources must accommodate multiple sensors
simultaneously. The ADT835 features a bath size of 90mm x 90mm with a depth of
155mm, enabling the calibration of multiple sensors in one operation. This capacity
supports the simultaneous calibration of up to four 50mm diameter sanitary temperature
sensors or up to forty 6.35mm diameter rod-type temperature sensors, signicantly
improving operational efciency
Innovative Dual Heating Technology for Enhanced Stability
Field environments often introduce challenges like power uctuations from heavy
equipment, inconsistent airow from industrial fans, and ambient temperature shifts
caused by variable-frequency air conditioning systems. These factors can signicantly
impact calibration bath performance and compromise temperature control stability.
The ADT835 overcomes environmental challenges with its innovative dual-zone
heating technology. An external heating system near the vapor chamber delivers
stable, consistent temperature control, while an internal heating element immersed
in the uid provides rapid, dynamic response to disturbances. This advanced design
greatly improves resistance to external interferences, ensuring reliable and accurate
performance—even in demanding eld conditions.
Accelerated Heating and Cooling for Maximum Efciency
Efcient calibration depends on fast temperature transitions, minimal stabilization times,
and sufcient bath capacity. The ADT835 delivers on all fronts with advanced variable-
speed prediction and non-overshoot control technology, achieving an accuracy error
band of ±0.1°C throughout the heating and cooling process.
ADT835-150 / ADT835PC-150: Heats to 150°C in 30 minutes, cools to -25°C in 45
minutes, and to -30°C in 55 minutes.
ADT835-250 / ADT835PC-250: Heats to 250°C in 55 minutes, cools to 100°C in 30
minutes, and to 33°C in 45 minutes.
These rapid thermal response times dramatically reduce calibration cycles compared to
traditional calibration baths, signicantly improving throughput and overall productivity.
Temperature Calibration Equipment
03
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
Optional Integrated Three-Channel High-Precision Process Calibrator
The ADT835 offers an optional built-in three-channel high-precision process calibrator,
designed to streamline eld operations. This feature eliminates the need to carry multiple
devices on-site.
The integrated calibrator combines the functions of a thermometer, multimeter, 24V
power supply, and HART handheld communicator, enabling the ADT835 to manage a
wide range of calibration tasks effectively.
Each channel is equipped with quick push connectors, allowing for tool-free, rapid
connections regardless of the connector type. Channel 1 serves as a reference
channel, compatible with smart secondary reference PRTs or user-provided reference
thermometers. Channels 2 and 3 are designated for device under test (DUT) connections,
supporting RTDs, thermocouples (TCs), temperature transmitters, HART temperature
transmitters, and temperature switches.
Remote Control for Parallel Operation
The ADT835 features advanced remote control capabilities to facilitate parallel
operations:
Point-to-Point Mode: Connects to a mobile phone or computer via Bluetooth or WiFi
hotspot, allowing direct operation of the bath from these devices.
Cloud Mode: Connects to the network through WiFi or LAN port, enabling remote
management of multiple calibration baths via mobile phones or computers in point-to-
point mode.
These smart remote control options enhance operational exibility and efciency.
Advanced Fluid Protection Design for Ease of Use and Maintenance
The ADT835 incorporates a professional uid protection design to ensure safe and
convenient operation. It features an integrated overow tank and drain port to manage
uid efciently and facilitate easy transport, mitigating environmental contamination
and safety risks. The bath and tank body are constructed from rust-resistant stainless
steel, which is easy to clean and durable, even in the presence of irritating or corrosive
contaminants.
The ADT835 also includes a sealed top cover with a hand-tight screw to effectively
prevent uid spill during transport and calibration. Additionally, a protective power switch
design minimizes the risk of oil mist accumulation on power switch contacts, enhancing
reliability and reducing failure likelihood. For user safety, a temperature warning icon
appears on the display when the liquid temperature exceeds 50°C, alerting users to
prevent accidental burns. These features collectively enhance the safety, usability, and
maintenance of the ADT835 calibration bath.
Automated Self-Calibration for Internal Reference Sensor
Periodic calibration is essential for maintaining temperature control accuracy in calibration
baths. Traditional methods involve manually recording and calculating errors at each
calibration point, a process that can be time-consuming and complex, often taking over
an hour.
The ADT835 simplies this with its automated self-calibration program. This feature
eliminates the need for manual data entry and calculations, streamlining the calibration
process and ensuring accurate temperature control with minimal user intervention.
04
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Temperature Calibration Equipment
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
SPECIFICATIONS
General Specifications
Specification Description
Power requirements
Power supply
110V: 100~120V, 50 Hz/60Hz, fuse: 8A 250V
220V: 200~230V, 50 Hz/60Hz, fuse: 4A 250V
Maximum power consumption: 800W
Size and weight
Main structure size: 7.5 × 16.2 × 15.2 in (191(W)×412(H)×387(D)mm)
Maximum size: 7.5 × 18.1 × 16.77 in (191(W)×460(H)×426(D)mm) (with handle, overow tube)
Weight: 35.27 Ibs (16 kg) /ADT835-155 and 35.94 Ibs (16.3 kg ) /ADT835PC-155
30.86 Ibs (14 kg )/ADT835-250 and 31.53 Ibs (14.3kg) ADT835PC-250
Environment
Operating temperature: 0°C~ 40°C
Guaranteed accuracy: 13°C~ 33°C
Storage temperature: -20°C~ 60°C
Humidity: 5%RH~95%RH, non-condensing
Altitude:
＜
2000 m
IP rating: IP20, indoor use only
Vibration: 2g
Impact: 5g
Package drop test: 1m
Warm-up time: 15 min
Working area
Bath size: 90mm*90mm
Working area: bath center
φ
75mm circular zone, 15mm above bath bottom, 65mm below the uid level, maximum depth
155mm
Heat transfer fluid
Maximum volume: 2.5L
Recommended uid at 150°C: DOW CORNING XIAMETER PMX-200 10cSt
Recommended uid at 250°C: DOW CORNING XIAMETER PMX-200 50cSt
Communication
USB-A, USB-B, LAN, WIFI, BLE
Electrical functions
Reference RTD channel (EXT.REF)
φ
4mm banana jacks, 6 PIN Lemo port, quick push wiring
DUT channels (CH1, CH2)
φ
4mm banana jacks, quick push wiring
Display
6.5 in (165 mm) color capacitive touch screen, 640*480, anti-reective panel, Dark or bright theme switchable
Communication update rate: 10 times/s, Display refresh rate: 4 times/s
Temperature units: °C, °F, K
Highest resolution: 0.001°C, adjustable
Languages
English, Chinese, Japanese, Russian, German, French, Italian, and Spanish
Warranty 1 year
Temperature specification
[1]
Models ADT835PC-150 / ADT835-150 ADT835PC-250 / ADT835-250
Range
[2]
-30°C~150°C 33°C~250°C
INT REF accuracy
[3]
± 0.1°C ± 0.1°C
EXT REF accuracy
[4]
± 0.05°C ± 0.05°C
Stability
[5]
± 0.01°C ± 0.015°C
Uniformity
[6]
± 0.02°C
± 0.03°C (≤200°C)
± 0.04°C (
＞
200°C)
Repeatability
[7]
0.04°C (internal reference)
0.01°C (external reference)
0.04°C (internal reference)
0.01°C (external reference)
Heating time
[8]
18 min (-30~23°C)
30 min (23~150°C)
20 min (23~100°C)
35 min (100~250°C)
Cooling time
[8]
45 min (150°C~23°C)
45 min (23°C~-25°C)
55 min (23°C~-30°C)
30 min (250°C~100°C)
45 min (100°C~33°C)
Typical time to stability
[9]
10 min 10 min
Temperature Calibration Equipment
05
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
[1] The following temperature specications are all based on the following conditions:
When the environmental temperature is between 13°C~33°C and the calibration bath is within one year after calibration, the condence
level is 95% (K=2), the bath is not open, the working area is the
φ
75mm circular zone of the bath center, and it is 15mm above the bath
bottom and 65mm below the uid level. The depth of the uid should be more than 130mm.
When the environmental temperature exceeds the range of 13°C~33°C, the stability and uniformity specication will be 1.25 times
larger.
When the bath is open, the stability and uniformity specication will be 1.25 times larger.
[2] The lower limit of controlling range can vary depending on the environmental temperature.
[3] The internal reference accuracy has taken into account the following sources of error including calibration uncertainty, stability,
uniformity and repeatability.
[4] The external reference accuracy is available for ADT835PC-150 and ADT835PC-250, the reference probe used is Accumac model
AM1730-12-ADT.
[5] Stabilty is dened as half of the difference between the maximum and minimum temperature variations of the heat transfer uid
within the working zone over a 10-minute period after the product has reached full stabilization.
[6] Uniformity is dened as half of the difference between the highest temperature point and the lowest temperature point in the valid
working area.
[7] Repeatability mainly considers the hysteresis and short-term stability of the reference sensor.
[8] Heating and cooling times are measured from the start of temperature control to when the setpoint is reached within the internal
accuracy error band. Actual times may vary depending on ambient temperature, AC power supply voltage, sensor load, and whether
the bath is covered during operation.
[9] The typical time to stability refers to the time taken for the temperature in the bath to reach the stability tolerance after the heating or
cooling time ends.
Input Specifications (Process Calibrator [PC] Option
）
Note: This specication reects the bath’s accuracy for up to one year following calibration, based on a condence level of K=2
Electrical specification
Reference RTD channel (EXT.
REF)
RTD measure
Range: (0~400)Ω
Accuracy: ±1.25mΩ@(0~50)Ω, ±0.0025%RD@(50~400)Ω
Resolution: 0.1mΩ
Temperature coefcient: ±1ppmF.S/°C@(0~13)°C and (33~50)°C
Excitation current: 0.75mA, current reversal
Measurement technology: 4-wire, 1S measure cycle
Type: Pt25, Pt100 SPRT
Standard type: ITS-90, CVD, IEC-751
Wiring methods: Lemo and quick push connector
DUT channels
(CH1, CH2)
Current measure
Range: (-30~30) mA
Accuracy: ±(0.01%RD+2μA)
Resolution: 0.1μA
Temperature coefcient: ±5ppm F.S/°C@ (0~13)°C and (33~50)°C
Input impedance: <10Ω
Voltage measure
Range: (-30~30)V, (-12~12)V
Accuracy: ±(0.01%RD+0.6mV)
Resolution: 0.1mV
Temperature coefcient: ±5ppmF.S/°C@ (0~13)°C and (33~50)°C
Input impedance: >1MΩ
Switch measure Mechanical switch or electrical switch
Loop power
24 V±10%
（with
Load)
,
24 V±1%
（
no Load), Max 60mA for supply power to temperature
transmitter and electronic thermometer
HART CH1 supports measure and adjust HART transmitter
RTD measure
Range: (0~400)Ω and (0~4000)Ω(auto)
Accuracy: ±2.0mΩ@(0~25)Ω, ±0.004%RD@(25~400)Ω, ±0.005%RD@(400~4000)Ω
(4-wire measure)
Resolution: 0.1mΩ
Temperature coefcient: ±2ppmF.S/°C@( 0~13)°C and (33~50)°C
Excitation current: 0.25mA, current reversal
Measurement technology: 2/3/4-wire, 1S measure cycle
RTD type: Pt10, Pt25, Pt50, Pt100, Pt200, Pt500, Pt1000, Cu10, Cu50, Cu100, Ni100, Ni120
Wiring methods: Lemo and quick push connector
TC measure
Signal range: (-75~75)mV
Accuracy: ±(0.01%RD+5μV)
Temperature coefcient: ±5ppmF.S/°C @(0~13)°C and (33~50)°C
TC type: S, R, B, K, N, E, J, T, C, D, G, L, U
Cold junction range: 0°C~ 50°C
Cold junction accuracy: ±0.2°C
06
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Temperature Calibration Equipment
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
Temperature sensor measurement specification
Channel Type Measurement Accuracy
Reference RTD
channel
(EXT.REF)
PT25
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.013 ±0.013 ±0.013 ±0.013 ±0.013 ±0.014 ±0.014
PT100
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.006 ±0.006 ±0.008 ±0.009 ±0.011 ±0.012 ±0.013
DUT channels
(CH1, CH2)
PT100
Temp.(°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.009 ±0.010 ±0.012 ±0.015 ±0.017 ±0.019 ±0.021
K-TC
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.14 ±0.13 ±0.13 ±0.13 ±0.14 ±0.15 ±0.15
N-TC
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.20 ±0.19 ±0.19 ±0.18 ±0.17 ±0.17 ±0.17
E-TC
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.09 ±0.09 ±0.08 ±0.08 ±0.08 ±0.09 ±0.09
J-TC
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.11 ±0.10 ±0.10 ±0.10 ±0.11 ±0.11 ±0.11
T-TC
Temp. (°C) -30 0 50 100 150 200 250
Accuracy (°C) ±0.14 ±0.13 ±0.12 ±0.12 ±0.11 ±0.11 ±0.11
Note 1: The measurement accuracy specication does not include the accuracy of the DUT itself;
Note 2: Thermocouple measurement accuracy is calculated based on the cold junction temperature of 0°C and does not include the error of the CJC
sensor.
Models ADT835PC-150 ADT835-150 ADT835PC-250 ADT835-250
Range -30°C~150°C -30°C~150°C 33°C~250°C 33°C~250°C
mA/mV/V
• •
measure
• •
Switch measure
• •
24V loop power
• •
HART communicator
• •
Quick push wiring
• •
INT reference
• • • •
EXT reference
• •
Self-calibration
• •
Documenting task
• •
Step test
• • • •
Thermal calculator
• • • •
Sensor library
• • • •
Snapshot
• • • •
Remote control
• • • •
Smart diagnosis
• • • •
USB stick update
• • • •
ADT835 Selection Guide
Temperature Calibration Equipment
07
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
Optional Accessories
Model Description Picture
9921 Carrying case with wheels
9090
Single clamp bracket
(For more details, see
ADT835 special jig
specication)
9091
Single circular bracket
(For more details, see
ADT835 special jig
specication)
9092
Adjustable multiple hole jig
(For more details, see
ADT835 special jig
specication)
AM17XX-12-ADT
Straight Secondary reference
PRT (see Additel catalog)
AM17XX-BEND-
ADT
Bend Secondary reference
PRT (see Additel catalog)
9070
Smart connector for reference
PRT
(for modifying user’s own
reference sensor)
9071
Connector Adapter from smart
connector to 4-wire with gold-
plated spades
(for calibrating the reference
sensor)
9072
Smart connector with clamps
for reference PRT
(for connecting to user’s own
reference sensor)
9203-4L
Silicon Oil, 4L
(10 cSt for -150
）
9204-4L
Silicon Oil, 4L
(50 cSt for -250)
Blank access cover Custom holes by users
9080
Compensation cable kit
(S, R, K, J, T, E, N)
Ordering Information
Model:
ADT835
ADT835PC
ADT835
Model Number
Temperature Range
(at 23
°C
):
150: -30
°C to 150°C
250: 33
°C to 250°C
150
110 V
Power Option:
110 V
220 V
Accessories
Standard Accessories
Model Quantity Picture
AC power cable
1 pc.
USB cable 1 pc.
Test leads, 1 red 1 black
(only ADT835PC-L-150/
ADT835PC-H-250)
1 pc.
Top sealing cover
1 pc.
Multiple hole Teon cover 1 pc.
Protection basket 1 pc
Fluid overow box
1 pc.
ISO 17025 Accredited
calibration
1 pc.
08
Corporate Headquarters
2900 Saturn Street #B
Brea, CA 92821, USA
Salt Lake City Office
1364 West State Rd. Suite 101
Pleasant Grove, UT 84062, USA
Temperature Calibration Equipment
Phone: 714-998-6899 Email: sales@additel.com
Rev # 20250620
ADT835 Special jigs
No. Name Function Picture
1
9090
Single clamp
bracket
Quick connect to the M4
thread hose on the bath
handle
For clamp single DUT
2 9091
Quick connect to the M4
thread hose on the bath
handle
Constrains multiple DUTs for
batch calibration
3 Protection basket
The mesh thermal protection
basket is quickly installed
in the tank. The sides and
bottom of the basket have
excellent temperature
uniformity, and the DUTs can
contact it at any place
4
Adjustable multiple
hole jig
Allows the ange, nut and
stem of special-shaped DUTs
to be immersed in the liquid
at the appropriate position,
and the height can be
easily adjusted. Suitable for
calibration of multiple sanitary
temperature sensors
5
Multiple hole Teon
cover
The PTFE cover provides
heat insulation. The default
is 9 *
φ
8mm holes, and the
quantity and diameter of holes
can be customized. Suitable
for calibration of precision
temperature sensors
Typical Application of ADT835 Special jigs
No. Application jigs Picture
1
Open single calibration
for 1 large dial bimetallic
thermometer
Single clamp
bracket
2
Open batch calibration for
40 rod type sensors
Single circular
bracket +
Protection basket
3
Open batch calibration for
4 temperature transmitters
or more
Single circular
bracket +
Protection basket
4
Open batch calibration for
4 sanitary sensors of 50
mm diameter
Adjustable multiple
hole jig
5
Closed precision
calibration for 9 precision
sensors
Multiple hole Teon
cover +
Protection basket
Note:
Open calibration is intended for batch calibration of low-precision temperature sensors, large dial low-precision sensors, or temperature transmitters.
Closed calibration is designed for precision temperature sensors or transmitters, featuring insulation to minimize heat loss.