iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
The Casio Pro Trek PRW-69 measures compass bearing, barometric pressure, pressure-derived relative altitude, and temperature. Casio publishes tolerances of ±10° for direction, ±3 hPa for pressure, ±75 m for altitude, and ±2 °C for temperature. These are manufacturer specifications—not independent test results—and the watch is intended for general outdoor reference, not precision measurement.
The key distinction is that a readable, finely stepped display does not guarantee the same level of real-world accuracy. In particular, the altimeter estimates changes in elevation from air pressure, so weather can shift its reading even when you have not moved. The details below refer to Casio’s PRW-69Y-1 product information and module 5673 specifications; features and stated tolerances should be understood in that context. Casio PRW-69Y-1 specifications · Casio module 5673 sensor specifications
What do the PRW-69 sensors measure?
The PRW-69’s Triple Sensor functions provide four kinds of outdoor information: magnetic direction, atmospheric pressure, relative altitude calculated from pressure, and temperature. They are useful for orientation, tracking trends, and checking approximate conditions. Casio cautions that the watch is not a special-purpose measuring instrument and that its readings are for general reference.
Free tools Windows power users keep installed
One-click scans. No signup required.
The product page describes the PRW-69Y-1, while the sensor tolerances below are listed for module 5673. Casio’s published figures are specifications, not results from an independent laboratory comparison. A reading’s usefulness also depends on conditions: magnetic interference affects direction, pressure changes affect altitude, and a sudden temperature change can affect barometer readings. Casio’s general measurement-function guidance
Popular on Amazon
- Valued Carpenter Pencil Set: You will get 2 pcs solid carpenter pencils with 26 piece 2.8 mm refills, 1 replaceable sharpener, 1 plastic storage box.The complete carpenter pencils combination allows you to finish your work faster and more easily
- Deep Hole Marker Pencil: The deep-hole construction pencils adopts 45mm elongated tip design, which is more convenient to mark in the small hole or in other tight areas that other carpenter markers cannot reach
- Carpenter Pencils with Sharpener: The sharpener is screwed into the top of the work pencil, which won't get lost either. Built-in pencil sharpener that keep the lead with pointed and smooth to Improves line of sight in fine work
- Stronger Solid Lead: This work pencil is matched with a 2.8 mm thick lead , which is much thicker and stronger during the drawing process of construction work, it will not break or damage easily
- Marks on Various Surfaces: 3 colors solid construction pencil can marks on various surfaces,such as metal, plastic, wood, paper etc. Ideals for woodworkers, contractors, craftsmen, builders, merchants and masons
How accurate is the PRW-69 compass?
Casio specifies direction accuracy within ±10°, with the stated guarantee applying from 10 °C to 40 °C. The LCD displays a bearing from 0° to 359° in 1° units; that fine display increment is not the same thing as a guarantee of 1° real-world accuracy. The analog bearing-hand indication has its own specification: within ±2 gradations. Module 5673 direction tolerance
What the compass reading means
The compass senses magnetic direction. If you want to use true north instead, the watch supports magnetic-declination correction; the displayed direction depends on the settings you use. It can display direction as one of 16 points, retain a bearing in bearing memory, and take approximately 60 seconds of continuous measurement, according to the PRW-69Y-1 product page.
When to trust—and when to check—the reading
Casio warns that strong magnetism and nearby metal or electrical sources can cause errors. Its examples include high-voltage and aerial wires, televisions, computers, and cellphones. Correct readings may also be impossible in some environments, including reinforced-concrete buildings, electric trains, boats, and aircraft. These are not small technicalities: a compass can report a stable-looking direction that is nevertheless unsuitable for navigation if the surrounding environment disturbs its sensor. Casio’s compass cautions
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Casio recommends two-point calibration when the watch disagrees with another compass, and before setting out on a climb or trek. Keep the watch away from magnetic sources and metal while taking a bearing. For serious trekking or mountain climbing, Casio says to carry another compass and confirm the watch’s reading with it. Casio two-point calibration guidance · Casio compass operating cautions
Also popular on Amazon
- Ergonomically Designed: Work in tight areas with a compact design that gets into tough spots
- Both tools are designed to fit into difficult to reach spaces
- Complete a wide range of applications with a high-performance motor that delivers up to 300 UWO, and an impact driver delivering up to 1,400 in-lbs of torque
- Both the DEWALT impact driver and drill driver feature integrated LED work lights with a convenient 20-second delay, ensuring enhanced visibility in dimly lit or challenging work areas
- One-Handed Loading - Keep one hand free with a 1/4 in. hex chuck that accepts 1 in. bit tips
How accurate is the barometer?
The pressure sensor’s published accuracy is within ±3 hPa (0.1 inHg), with the stated guarantee applying from -10 °C to 40 °C. The display covers 260 to 1,100 hPa, or 7.65 to 32.45 inHg, in 1 hPa units. A 1 hPa display step does not mean each reading is accurate to within 1 hPa; the manufacturer’s stated tolerance is the more relevant figure. Module 5673 pressure tolerance · PRW-69Y-1 pressure range and display units
What pressure trends can tell you
The PRW-69 provides a pressure-tendency graph, a pressure-differential graphic, and a pressure-change alert. These features help you notice whether pressure is rising or falling rather than relying on one isolated number. Casio says the barometric graph can give an idea of upcoming weather conditions, but it should not replace precision instruments used for official weather prediction and reporting. The watch is best treated as a personal trend reference, not a source of official forecasts.
Temperature is one reason to be cautious about an individual pressure reading: Casio explicitly notes that sudden temperature changes can affect pressure-sensor readings. If a value seems inconsistent with conditions, consider whether the temperature has changed and look at the pattern over time rather than treating one reading as conclusive. Casio pressure-sensor and barometric-graph guidance
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
How accurate is the PRW-69 altimeter?
Casio specifies altimeter measurement accuracy within ±75 m (246 ft.). The stated measuring range is -700 to 10,000 m (-2,300 to 32,800 ft.), and the display unit is 1 m (5 ft.). Those figures describe different things: range is the span the watch can measure, display unit is the increment shown, and the published tolerance is the stated accuracy. A 1 m display unit is not a promise that the actual elevation is correct to within 1 m. Module 5673 altimeter specification · PRW-69Y-1 altimeter range and units
Also popular on Amazon
- 【Great Compatibility】This Katerk 1/4 inch hex shank bit holder is specifically designed for 1/4 inch hex shank drill bits. It's compatible with most 1/4 fast hex handles, hex sockets, various electric screwdrivers, and handheld screwdrivers. The bit holder makes it a valuable addition for any handyman.
- 【Secure and Safe】Built with a secure backup nut design, each drill bit holder securely locks onto your bits, ensuring they stay firmly in place. Additionally, our bit holder incorporates a high-quality steel ball rolling design that holds up to several kilograms of weight, ensuring your various drill bits don't fall off.
- 【Easy One-Handed Operation】The bit holder for impact driver allows you to change bits single-handedly, simplifying your workflow. Its multi-color design further allows for quick identification of the drill bit you need.
- 【Compact and Convenient】Thanks to its compact size, this 1/4 inch bit holder is easy to carry around. The bit holder allows for easy attachment to various tools, making this a convenient addition to your construction accessories. The Katerk bit holder is cast from high-quality alloy material, promising a long product lifespan. Despite its rugged strength, the bit holder remains lightweight, making it portable.
- 【Cool Christmas Gift For Men Stocking Stuffers】 This screwdriver bit holder, driver bit holder, impact bit holder, can be given as a gift to your loved one, especially for anyone involved in construction or electrical work. It's a must-have for stocking stuffers for men and women, tools gifts for dad, tech gadgets for men, gifts for dad, gifts for him, gifts for husband, gifts for boyfriend, cool gadgets for men, and cool gifts for dad.
Why the altitude can drift while you stay put
The watch does not directly measure geometric elevation. It estimates relative altitude from changes in barometric pressure. Because weather also changes air pressure, a pressure shift can look like an altitude change to the watch even when your actual elevation is unchanged. The displayed altitude is therefore most meaningful when calibrated against a known local elevation and interpreted with awareness that atmospheric conditions can move the estimate. Casio recommends regular calibration against local altitude or elevation indications. Casio altitude calibration guidance
Measurement intervals
The PRW-69 offers selectable altitude measurement intervals of 5 seconds or 2 minutes, with readings every second during the first 3 minutes. A shorter interval can provide more frequent updates, while a longer interval spaces readings farther apart. Neither setting removes the underlying dependence on atmospheric pressure or changes the manufacturer’s stated accuracy.
Can the thermometer measure outdoor air temperature?
The thermometer displays from -10 °C to 60 °C (14 °F to 140 °F) in 0.1 °C (0.2 °F) units. Casio specifies temperature-sensor accuracy within ±2 °C (3.6 °F), with the stated guarantee applying from -10 °C to 60 °C. The display’s 0.1 °C increment is resolution, not a claim of tenth-of-a-degree accuracy. Module 5673 temperature tolerance · PRW-69Y-1 thermometer range and units
Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallCrashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteCasio’s published tolerance does not establish that every reading, in every wearing position or setup, equals the surrounding air temperature. Treat the watch’s temperature as an estimate rather than a laboratory reading. The available specification alone does not support a more specific claim about how a particular wearing position affects the result.
Also popular on Amazon
- Long Nib and Deep Hole Marker: Our mechanical carpenter pencil with 45mm nib is designed for easy marking of deep holes or narrow areas. These construction pencils are the great choice for woodworking tools, construction tools, carpenter tools, contractor tools, wood carpentry tools and architect tools
- Extra Refills in 2 Colors for Versatile Marking: The construction mechanical pencil comes with 12 extra 2.8mm refills, including 6 red and 6 black refills. The black refill is suitable for light surfaces, while the red wax is perfect for dark surfaces. Our carpenter mechanical pencil makes sure that you'll have an ample supply for extended use
- Built-in Sharpener: Our construction pencil comes with a built-in sharpener to ensure the mechanical pencil tip is always sharp and ready for use. Never buy an extra pencil sharpener again. A great tool for any woodworker pencil, contractor pencils. The refill can easily be extended or retracted with a simple click of the pencils mechanical, allowing you to work more efficiently and accurately
- Portable Clip Design: Our deep hole construction pencil features a portable clip design, easy to carry and attach to your pocket or tool box, so that you can keep the carpenter pencils mechanical close at hand, making it a convenient tool to have on the go. Great gifts choice for carpenters
- Stronger Pencil Lead: The black refills are made of lead, sturdy and smooth. The red refills are made of wax, clear and light. These marking pencils are much thicker and stronger than normal pencils during the marking process of construction work, suitable for various surfaces, such as glasses, metal, boards, floors, walls, furniture, etc. The written marks can be easily wiped with a wet paper towel when needed
How should you calibrate and use the readings outdoors?
Use calibration and cross-checks to make the readings more useful, but keep in mind that calibration does not turn these general-reference functions into precision instruments.
- Before a climb or trek, calibrate the compass. Casio recommends two-point calibration if the watch’s direction differs from another compass, and before setting out on a climb or trek. Follow the module 5673 manual’s calibration procedure, and perform it away from magnetic interference and metal.
- Check the compass against a second reference when navigation matters. Casio advises taking another compass for serious trekking or mountain climbing and using it to confirm readings. If the watch and the reference disagree, do not assume the watch is right; first consider calibration and nearby interference.
- Set altitude at a known elevation when available. Calibrate against a local altitude or elevation indication. Recalibrate when you have reliable local elevation information, because weather-related pressure changes can shift the pressure-derived estimate.
- Use pressure as a trend, not an official forecast. Read the tendency graph and pressure changes as general clues. Account for sudden temperature changes, which Casio says can affect the sensor.
- Interpret temperature as an estimate. Do not equate a displayed tenth of a degree with that level of accuracy or assume that a watch reading always equals ambient air temperature.
What does the accuracy specification mean in practice?
Accuracy, resolution, and measuring range answer separate questions. Range tells you the span a function is designed to cover; resolution tells you the size of the displayed increments; accuracy is the manufacturer’s stated tolerance. The PRW-69’s altitude display, for example, uses 1 m units, but its published accuracy is ±75 m. Reading all three values together avoids mistaking a detailed display for a precision measurement.
- Compass: 0°–359° range, 1° LCD units, and ±10° stated direction accuracy from 10 °C to 40 °C.
- Barometer: 260–1,100 hPa (7.65–32.45 inHg) range, 1 hPa units, and ±3 hPa (0.1 inHg) stated accuracy from -10 °C to 40 °C.
- Altimeter: -700 to 10,000 m (-2,300 to 32,800 ft.) range, 1 m (5 ft.) units, and ±75 m (246 ft.) stated accuracy; it is pressure-derived and weather-sensitive.
- Thermometer: -10 °C to 60 °C (14 °F to 140 °F) range, 0.1 °C (0.2 °F) units, and ±2 °C (3.6 °F) stated accuracy from -10 °C to 60 °C.
Casio’s manual frames the functions as general reference rather than special-purpose measurement. They can help with outdoor awareness and tracking changing conditions, but the published specifications do not establish performance in every environment or make the watch a substitute for dedicated precision instruments. Casio measurement-function disclaimer
Recommended Free Tools
Frequently Asked Questions
How far back does the PRW-69 pressure tendency graph go?
Casio’s PRW-69Y-1 product page says the graph covers the past 42 hours of pressure readings. That history can help put a current pressure value in context, but Casio describes the graph as a general aid for getting an idea of weather conditions, not official forecasting.
How accurate is the PRW-69’s timekeeping if sensor accuracy is not involved?
Casio lists timekeeping accuracy of ±15 seconds per month when time calibration by signal is unavailable. That is a clock specification, separate from the compass, pressure, altitude, and temperature tolerances.
Are the PRW-69 accuracy numbers independent test results?
No. The ±10° compass, ±3 hPa pressure, ±75 m altitude, and ±2 °C temperature figures are Casio’s published module specifications. They are not independent laboratory measurements.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
