• Pressure ranges up to 60,000 psi (4,200 bar)

• 0.02%, 0.05%FS or 0.1%RD accuracy

• Fully temperature compensated accuracy

• Every model measures Gauge or Absolute Pressure

• Built-in Barometer

• Touchscreen display

• Intrinsically safe version 685Ex (optional)

• Bluetooth and USB communications

• Data logging (optional)

• IP67 rated

• Communicates with Additel's Link Mobile App

• ISO 17025-accredited calibration w/data included

Looking for the most advanced, best performing and modern digital pressure gauge on the market? Congratulations, you’ve just found it! Additel’s ADT685 digital pressure gauges are in a class of their own with an amazingly easy to use and read touchscreen display. The all new modern menu structure and control interface bring a new and refreshing experience to gauge work. This completely new way of interfacing with our gauges makes the ADT685 gauges a real pleasure to use. With microprocessor technology, state-of-the-art silicon pressure sensors and plenty of onboard storage capacity, these attractive and fully temperature compensated gauges will provide the performance, durability and reliability you’ve come to expect from genuine Additel products. To provide support for intrinsically safe needs, the ADT685Ex comes ready to provide pressure measurements and recordings in the most demanding of environments. Each Additel 685 is also IP67 rated to protect your investment in dusty and/or wet environments

A Modern User Experience:

Additel has gone above and beyond to provide our customers with the best possible experience when using these new and revolutionary gauge. The 3.4 inch touchscreen display comes with a protective replaceable tempered glass screen and is a refreshing update to the traditional push button or blister pad interface. With an easy to navigate menu structure and fast touchscreen response, you will find these ADT685 gauges simple yet powerful to use. The easy to read display isn’t just fun to use, but it’s built rugged to handle the demands of a busy technician in the field or the laboratory.

Every model measures Gauge or Absolute Pressure:

The Additel 685 Digital Pressure Gauges contain a built-in barometer sensor which allows for the pressure reading to display in gauge pressure or absolute pressure with a simple menu selection. The built-in barometer is calibrated and certified to an accuracy of 50 Pa. With this unique feature, the ADT685 can be a solution for three common applications: gauge pressure measurement, absolute pressure measurement, and barometric or atmosphere pressure measurement. Having an Additel as your gauge will always give you the ability to do more with one instrument!

Datalogging Option:

We've added the option to do stand-alone data logging with the ADT685. Now you can record more than 10M records internal to the 685 series. Each record includes date, time, pressure and temperature readings. Download the logged data with our free Additel/Land software or you can purchase our Additel/Log II for real-time logging and data analysis. Additel's 685 digital pressure gauges are unmatched in performance and reliability. You get nothing but the best when you buy Additel Products!

• Pressure ranges up to 60,000 psi (4,200 bar)

• 0.02%, 0.05% FS or 0.1% RD Accuracy

• Black and White Touchscreen Display

• Every model measures Gauge or Absolute Pressure

• Built-in Barometer

• Intuitive Smartphone Like Interface

• Bluetooth and USB communication

• Data logging (optional)

• Communicates with Additel's Link Mobile App (optional)

• IP67 Rated

DescriptionDigital Pressure GaugeIntrinsically Safe Digital Pressure Gauge
Intrinsic Safety & European ComplianceCECE marked, ATEX certified intrinsically safe, II 1G EX ia IIC T4 Ga
Accuracy (For detailed accuracy, please see pressure range table)685(Ex)-02 : 0.02% of full span
685(Ex)-05 : 0.05% of full span
685(Ex)-RD: 0% to 20% of Range: 0.02% of full span, 20% to 110% of Range: 0.1% of reading, Vacuum: 0.25% of full span [1][2]
Barometric Accuracy (Built-in barometer)50Pa
Gauge TypesGauge pressure, compound pressure, absolute pressure, differential pressure and barometric pressure
DisplayTouch screen (3.4'' FSTN segment capacitive) - 5 1/2 full digits
Screen protector: tempered glass film (replaceable)
Display rate: 3 readings per second (default setting). Adjustable from 10 readings per second to 1 reading every 20 seconds
Pressure UnitsPa, kPa, MPa, psi, bar, mbar, kgf/cm2, inH2O, mmH2O, inHg, mmHg and 3 customized unit
EnvironmentalCompensated Temperature: 14°F to 122°F (-10°C to 50°C)
Operating Temperature: 14°F to 122°F (-10°C to 50°C)
Storage Temperature: -4°F to 158°F (-20°C to 70°C)
Humidity: 0 - 95%, Non-condensing
Pressure Port≤15,000 psi: 1/4NPT male, 1/2NPT male, 1/4BSP male, 1/2BSP male, M20×1.5 male
>15,000 psi: 1/4HP female or 1/4HP male, *1/4HP female: Autoclave F-250-C, 9/16" - 18 UNF-2B, *1/4HP male: Autoclave M-250-C, 9/16" - 18 UNF-2A
Differential Pressure: Barb fitting
Other connections available per request
PowerBattery: Three AA alkaline batteries (included)
Battery life: 1500 hours typical
Power auto-off: user selectable
External power: 110/220 V adapter (5 VDC) (optional, excl ADT685Ex)
EnclosureCase material: 304 SS
Wetted parts: 316 SS[3]
Dimensions: 4.65" (118mm) width X 1.77" (42mm) depth X 7.01" (178mm) height
Weight: 1.50 lbs. (0.68 kg)
ComplianceProtection Level: IP67
Vibration: 5 g (10-500 Hz)
Shock Resistance: 8 g/11 ms
Data Logging (Available on with data logging tion ADT685-...-DL)Data storage: 10,000,000 records
Rate: user selectable from 0.1 to 9999.9 second intervals
CommunicationUSB Type-C and Bluetooth included RS-232 or RS-485 [4] (optional)
4 - 20 mA Output[4]3.2 μA
Warranty1 year
[1] FS = -14.5 psi
[2] Applicable ADT685-RD-CPX
[3] Wetted parts material types may vary by pressure range. Please refer to manual or contact Additel for more information.
[4] 4-20mA output and RS-485 not available in ADT685Ex models.
Gauge Pressure [1]
P/NPressure RangeMedia [2]AccuracyBurst Pressure
V15-15-1G0.02 (0.05)N/A
GP220.16G, L0.05N/A
GP550.35G, L0.050.1
GP10100.7G, L[3]0.02 (0.05)0.1
GP15151G, L[3]0.02 (0.05)0.1
GP30302G, L[3]0.02 (0.05)0.1
GP50503.5G, L0.02 (0.05)0.1
GP1001007G, L0.02 (0.05)0.1
GP15015010G, L0.02 (0.05)0.1
GP30030020G, L0.02 (0.05)0.1
GP50050035G, L0.02 (0.05)0.1
GP60060040G, L0.02 (0.05)0.1
GP1K100070G, L0.02 (0.05)0.1
GP1.5K1500100G, L0.02 (0.05)0.1
GP2K2000140G, L0.02 (0.05)0.1
GP3K3000200G, L0.02 (0.05)0.1
GP5K5000350G, L0.02 (0.05)0.1
GP10K10000700G, L0.02 (0.05)0.1
GP15K150001000G, L0.05 (0.1)0.11.5×
GP20K200001400G, L0.05 (0.1)N/A1.5×
GP25K250001600G, L0.05 (0.1)N/A1.5×
GP30K300002000G, L0.05 (0.1)N/A1.5×
GP36K360002500G, L0.05 (0.1)N/A1.5×
GP40K400002800G, L0.05 (0.1)N/A1.35×
GP50K500003500G, L0.1 (0.2)N/A1.2×
GP60K600004200G, L0.1 (0.2)N/A1.1×
[1] Sealed gauge pressure for above 1,000 psi
[2] G=Gas, L=Liquid
[3] 0.02% FS for gas media only
Barometric Pressure
P/NPressure RangeMediaAccuracyBurst Pressure
BP60 kPa110 kPaG40 Pa
Absolute Pressure
P/NPressure RangeMedia [1]Accuracy (%FS)Burst Pressure
AP550.35G, L0.1
AP10100.7G, L0.1
AP15151G, L0.1
AP30302G, L0.1
AP50503.5G, L0.1
AP1001007G, L0.05 (0.1)
AP30030020G, L0.05 (0.1)
AP50050035G, L0.05 (0.1)
AP1K100070G, L0.05 (0.1)
AP3K3000200G, L0.05 (0.1)
AP5K5000350G, L0.05 (0.1)
[1] G=Gas, L=Liquid
Differential Pressure
P/NPressure RangeMediaAccuracy (%FS) [1]Burst PressureStatic Pressure Range
DP1±1±2.5G0.05[2]100×±10 psi
DP2±2±5.0G0.05[2]100×±10 psi
DP5±5±10G0.05[2]50×±10 psi
DP10±10±25G0.05[2]20×±10 psi
DP20±20±50G0.0520×±10 psi
DP30±30±75G0.0520×±10 psi
DP50±50±125G0.05±10 psi
DP100±100±250G0.02±15 psi
DP150±150±350G0.0250 psi
DP300±300±700G0.0250 psi
Compound Pressure
P/NPressure RangeMedia [1]AccuracyBurst Pressure
CP5±5±0.35G0.02 (0.05)0.1
CP10±10±0.7G0.02 (0.05)0.1
CP15±15±1G0.02 (0.05)0.1
CP30-15 to 30-1 to 2G0.02 (0.05)0.1
CP100-15 to 100-1 to 7G, L0.02 (0.05)0.1
CP300-15 to 300-1 to 20G, L0.02 (0.05)0.1
CP500-15 to 500-1 to 35G, L0.02 (0.05)0.1
CP600-15 to 600-1 to 40G, L0.02 (0.05)0.1
CP1K-15 to 1000-1 to 70G, L0.02 (0.05)0.1
[1] G=Gas, L=Liquid
[2] FS specification applies to the span of the range


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Rubber boot
AAA alkaline battery (3 pcs)
USB cable type-C
Hanging strap
RS-485 Adapter (for RS-485 models only)
4-20mA cable (for 20MA models only)
RS-232 Ex adapter (for EX RS-232 models only)
Silicone tube - 1 meter each (2 pcs for DP models only)
ISO 17025 Accredited Calibration Certificate
Optional Accessories
Model numberDescription
9903Carrying Case for one digital pressure gauge
9810110V/220V external power adapter (DC 5V)
9502Additel/Log II real time data logging and graphical software for ADT 685 and ADT 685Ex
9530-BASICAdditel/Acal Automated calibration software with asset management, basic version
9530-NETAdditel/Acal Automated calibration software with asset management, network version, Includes server installation and 1 user license
9050USB to RS232 (DB9/M) Adapter
9050-EXTRS 232 (DB9/M) extension cable, 9 feet