The AUTOOL PT503 is a compact mini differential pressure gauge for positive pressure, negative pressure, and differential pressure measurement. It is designed for portable on-site testing, automotive intake, brake booster, exhaust, crankcase or crankshaft-related pressure checks, and quick mobile diagnostic work. With a high-precision pressure sensor, 6 switchable pressure units, data hold, a backlit LCD display, and a reinforced portable body, PT503 helps users capture and record pressure changes clearly in workshop or field environments.
Positive / Negative / Differential±0.5%FS Accuracy6 Pressure UnitsData Hold
-101~200kPaTesting Range
0.1kPakPa Resolution
2×AAABattery Power
3 YearsWarranty
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Key Features
Key Features
PT503 combines accurate pressure sensing, a readable backlit display, one-button data hold, 6-unit switching, portable body design, and adapter support in a compact diagnostic gauge.
High-Precision Sensor
Measures from -101kPa to 200kPa with accuracy up to ±0.5%FS, helping users capture subtle pressure changes during diagnostic and maintenance work.
Three Pressure Types
Supports positive pressure, negative pressure, and differential pressure measurement for compact automotive and general pressure testing workflows.
1.8-Inch Backlit LCD
The LCD backlit display helps users read pressure values clearly in bright, dim, workshop, or field testing environments.
One-Button Data Hold
Lock the current reading for easier recording, comparison, or reporting when the pressure value needs to remain visible after measurement.
6 Switchable Units
Switch between psi, inHg, kPa, mbar, bar, and mmHg without manual conversion, making the pressure result easier to match to different service references.
Portable Body & Adapters
The 125 × 56 × 30mm body weighs about 120g and works with the included measurement adapters shown in the package image for different pressure ports.
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Specifications
PT503 Product Specifications
Review the key measurement, power, display, environment, and body specifications before choosing PT503 for compact pressure testing.
Measurement
Product
AUTOOL PT503 Mini Differential Pressure Gauge
Pressure Types
Positive pressure, negative pressure, and differential pressure
Auto Power-OffAbout 5 minutes of no operation or no pressure
Applications
Applications
Use PT503 for compact automotive pressure, negative-pressure, and differential-pressure checks when the measurement range and connector setup match the test point.
Intake Manifold Testing
Use PT503 to support intake system pressure or negative-pressure checks during engine diagnostic work.
Brake Booster Testing
Assist brake booster pressure or vacuum-related checks with the correct connector and safe measurement setup.
Crankcase Pressure Checks
Use the gauge for crankcase or crankshaft-related pressure variation checks during vehicle maintenance and troubleshooting.
Exhaust And General Checks
Support exhaust and general low-pressure diagnostic checks within the PT503 measurement range and suitable media conditions.
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How To Use
How To Use
Install batteries, let the gauge zero in open air, connect the correct hose and adapter, select the display unit, and lock the reading when you need to record the result.
Install Batteries And Power On
Install 2 × 1.5V AAA batteries. Power on the gauge without pressure applied so the startup auto-zero and atmospheric pressure calibration remain accurate.
Connect Hose And Adapter
Choose the correct hose and adapter for the test port. Check the hose, adapter, and connector condition before starting measurement.
Select Unit And Backlight
Use the unit function to switch between psi, inHg, kPa, mbar, bar, and mmHg. Use the backlight function when the working area is dim.
Hold And Record Data
Use the data hold function to lock the reading before recording, comparing, or reporting the pressure value.
Use Notes
Do not power on the PT503 while pressure is already applied.
Do not exceed the 200kPa maximum measurement range.
Avoid squeezing or sharply bending the silicone tube during testing.
Replace the batteries if the battery indicator flashes or the reading becomes unstable.
The gauge can automatically power off after about 5 minutes of no operation or no pressure.
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Product Comparison
Product Comparison
PT503 is the mini portable option for quick on-site pressure testing. Compare it with PT520 and PT530 if you need a larger screen, data storage, higher accuracy, or a wider measurement range.
Choose PT503 IfYou need a mini portable gauge with a 1.8-inch display, -101~200kPa range, ±0.5%FS accuracy, and simple field use.
Choose PT520 IfYou prefer a larger 2.8-inch display, 29 groups of data storage, and higher ±0.3%FS accuracy for a more complete digital manometer setup.
Choose PT530 IfYou need a higher-level dual-port differential pressure gauge with -100~300kPa range, ±0.25%FS accuracy, storage support, magnetic back, button light, and tool box configuration.
Shared ApplicationsAll three models can support intake manifold, brake booster, crankcase, and suitable pressure testing scenarios when the test setup is correct.
Decision CheckCompare portability, display size, data storage, accuracy, range, adapters, application scope, and budget before ordering.
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What Is In The Box
What Is In The Box
The packing image shows the PT503 main unit and included accessories. Use the package image as the final visual reference before ordering.
Main UnitAUTOOL PT503 mini differential pressure gauge
DocumentationAUTOOL PT503 user manual
PackageRetail box shown in the package image
AdaptersMeasurement adapters shown in the package image
Hose / TubingMeasurement hose and tubing shown in the package image
Support3-year warranty and lifetime maintenance support
Manual And Downloads
Manual And Downloads
Download the AUTOOL PT503 EN-DE manual for setup, unit switching, data hold, display reference, measurement preparation, and operation guidance.
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AUTOOL PT503 User Manual
Open the PDF manual for pressure unit switching, data lock, measurement setup, display icons, battery use, and safe operation.
Contact AUTOOL Store for adapter confirmation, unit switching, data hold, battery setup, differential pressure testing, manual support, or model selection help.
Confirm the PT503 measurement range, battery requirement, connector setup, startup condition, and use limits before measurement.
Do Not Exceed 200kPa
PT503 measures up to 200kPa. Do not use it beyond the maximum measurement range.
Power On Without Pressure
The gauge performs startup zeroing and atmospheric pressure calibration. Powering on under pressure may cause inaccurate readings.
Use 2×AAA Batteries
PT503 is powered by 2 × 1.5V AAA batteries. Replace batteries if the battery indicator flashes or readings become unstable.
Check Hose And Adapter
Before testing, check the hose, adapter, battery condition, and connector fit to avoid unstable or incorrect measurements.
Avoid Tube Compression
Do not squeeze, sharply bend, or block the silicone tube during measurement, because this may affect the pressure reading.
Use Suitable Media
Use PT503 only with suitable non-corrosive test media and the correct connector setup for the pressure port being measured.
Additional Use Reminders
Keep the gauge away from strong vibration, strong magnetic fields, and rapid temperature changes during measurement.
Use the correct pressure unit before recording values.
Use data hold before writing down or comparing readings.
For a larger display, data storage, or higher accuracy, compare PT503 with PT520 and PT530 before ordering.
Related Products
Related Products
Compare related AUTOOL digital manometers and pressure gauge tools before choosing the right tester for differential pressure, oil pressure, brake pressure, or workshop diagnostics.
SALE
Select options
This product has multiple variants. The options may be chosen on the product page
Select options
This product has multiple variants. The options may be chosen on the product page
Questions And Answers
These answers cover pressure types, measurement range, units, batteries, data hold, operation, startup zeroing, preparation checks, and PT503 / PT520 / PT530 model selection.
PT503 can measure positive pressure, negative pressure, and differential pressure. It is suitable for compact automotive diagnostic pressure checks when the pressure range and connector setup match the test point.
The PT503 testing range is -101kPa ~ 200kPa. Its accuracy is up to ±0.5%FS, and its kPa resolution is 0.1kPa.
PT503 supports 6 pressure units: psi, inHg, kPa, mbar, bar, and mmHg. Switch to the correct unit before recording or comparing readings.
PT503 uses 2 × 1.5V AAA batteries. Replace the batteries if the battery indicator flashes, the display becomes unstable, or the gauge cannot operate normally.
Yes. PT503 supports a data hold function. Use it to lock the current reading when you need to record, compare, or report the pressure value.
Use the unit function to switch between psi, inHg, kPa, mbar, bar, and mmHg. Use the backlight function when the working area is dim. Refer to the PT503 manual for the exact key operation sequence.
No. Power on the gauge without pressure applied. PT503 performs startup zeroing and atmospheric pressure calibration, so powering on under pressure may cause inaccurate measurements.
Check the batteries, hose, adapter, connector fit, and pressure range before testing. Avoid squeezing the silicone tube, and do not use the gauge beyond the 200kPa maximum range.
PT503 focuses on mini portability and quick field testing. PT520 is a larger digital manometer option with a bigger display, data storage, and higher accuracy. PT530 is the higher-level option with a wider -100~300kPa range, higher ±0.25%FS accuracy, storage support, magnetic back, button light, and tool box configuration.
Warranty And Contact
Warranty And Contact
For PT503 setup, adapter confirmation, battery use, unit switching, data hold, differential pressure testing, warranty, or PT503 / PT520 / PT530 model selection support, contact AUTOOL Store.
Pre-Sales And Product Support
Use support if you need help confirming whether PT503 fits your intake, brake booster, exhaust, crankcase, or general pressure test needs, or if you need help choosing between PT503, PT520, and PT530.
3-year warranty for eligible non-human damage cases
Lifetime maintenance support
Manual download and setup confirmation
Adapter, hose, battery, unit switching, and data hold support
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