Solinst Model 104 Sonic Water Level Meter
The Solinst Model 104 Sonic Water Level Meter is a portable instrument for measuring static depth to water without lowering a tape or water-contact probe into the well. It sends a sound pulse down the well and calculates the distance to the water surface from the returning echo.
Designed for wells, piezometers, sounding tubes, and other suitable closed pipes, the Model 104 is useful where access makes conventional tape measurements difficult. Because the measurement does not require equipment to contact the water, it reduces the equipment decontamination associated with moving a submerged probe between wells.
Non-Contact Depth-to-Water Measurement
The connected sonic probe is positioned at the well opening while readings appear on the handheld control unit. Measurements can be displayed in imperial or metric units. Temperature compensation and adjustable measurement settings help account for conditions that affect the returning sound signal.
- Acoustic measurement: Measures depth to static water without lowering a probe to the water surface.
- Portable control unit: Handheld display and keypad for taking readings and adjusting settings.
- Adjustable detection range: Minimum and maximum range settings help exclude unwanted reflections.
- Measurement offsets: Settings accommodate the position of the probe relative to the measurement reference point.
- Flexible display units: Select imperial or metric measurements.
Check Well Conditions Before Selecting a Sonic Meter
Reliable acoustic measurements depend on the well opening, casing configuration, background noise, and depth to water. Casing diameter changes and other internal features can create unwanted echoes. A suitable seal around the probe helps keep the sound pulse inside the well and reduce interference from outside noise.
For wells larger than 8 inches in diameter, Solinst recommends a drop tube extending from the top of the well to just below the water surface. A drop tube may also be needed where significant casing changes or perforated sections interfere with the signal. The included plastic disc helps cover the well opening but does not replace a required drop tube.
What Comes with the Solinst 104?
- Solinst Model 104 control unit
- Connected sonic probe with a 6-foot (1.8-meter) cable
- Six AA batteries
- Plastic disc for covering the well opening
- Solinst Field Bag
Ordering reference: Solinst part number 115747. Contact Activated Carbon Depot for help reviewing your well configuration before ordering.
Solinst Model 104 Technical Specifications
| Measurement method | Acoustic measurement of static depth to water |
|---|---|
| Manufacturer-stated operating range | 3–600 m (9–2,000 ft), depending on well conditions and setup |
| Manufacturer-stated accuracy | 3 cm (0.1 ft); measurement performance depends on installation, settings, and well conditions |
| Display resolution | 1 cm in metric mode; 0.05 ft in imperial mode |
| Reading update time | Approximately 1 second at 150 m (500 ft); approximately 4 seconds at 600 m (2,000 ft) |
| Measurement units | Selectable metric or imperial units |
| Probe cable length | 1.8 m (6 ft); connects the wellhead probe to the control unit |
| Power supply | Six replaceable AA alkaline batteries |
| Battery life | Up to 500 hours of use |
| Operating temperature | −20°C to 45°C |
| Control unit dimensions | 19 × 9 × 4 cm |
| Control unit weight | 390 g (14 oz) |
| Manufacturer warranty | Three years, subject to Solinst warranty terms |
| Solinst part number | 115747 |
Display resolution describes the increments shown on the screen; it does not represent measurement accuracy. The maximum operating depth is not guaranteed for every well. Review casing diameter, obstructions, temperature conditions, and drop-tube requirements before use.
Applications for the Solinst 104 Sonic Water Level Meter
The Model 104 is designed for taking static depth-to-water readings in wells, piezometers, sounding tubes, and suitable closed pipes. Its acoustic measurement method is useful when lowering a conventional water level tape is difficult or when avoiding water contact is a priority.
- Static water level checks in groundwater monitoring wells
- Measurements through suitable well-cap openings
- Wells with narrow or difficult access for conventional probes
- Field surveys requiring measurements at multiple wells
Well Setup and Measurement Limitations
The Model 104 needs a suitable acoustic path between the wellhead and the water surface. Well geometry, casing condition, temperature differences, and background noise can affect the returning signal. Review these conditions before selecting the meter.
- Well opening: Position the probe securely and limit gaps around the opening to help retain the sound pulse and reduce outside noise.
- Larger wells: Solinst recommends a drop tube for wells larger than 8 inches in diameter. The tube should extend from the top of the well to just below the water surface.
- Casing changes: Significant changes in casing diameter or perforated sections may require a drop tube to reduce unwanted reflections.
- Background noise: Pump noise and other interference can affect readings. Adjust the measurement range according to the well configuration.
- Shallow water: Water levels shallower than the manufacturer-stated minimum range of 3 m (9 ft) are outside the specified operating range.
- Equipment protection: The control unit and sonic probe are not waterproof and must not be submerged.
The supplied plastic disc helps cover the well opening. It does not replace a drop tube when one is required.
Solinst 104 Sonic Meter vs. Tape Water Level Meters
Choose a meter based on your measurement method, well configuration, and field requirements. The Model 104 measures acoustically from the wellhead, while conventional tape meters detect water with a probe lowered into the well.
| Model | Measurement approach | When to consider it |
|---|---|---|
| Solinst 104 Sonic | Sound pulse measures static depth to water without lowering a probe to the water surface. | Suitable wells where avoiding water contact or accessing the water with a tape is a priority. |
| Solinst 101 P7 | A water-contact probe and graduated flat tape provide a manual depth reading. | Routine manual water level measurements where the probe can reach the water. |
| Solinst 102 P10 | A narrow water-contact probe on graduated cable provides a manual depth reading. | Narrow access points where probe clearance is an important selection factor. |
| Solinst 101D DrawDown | A tape-based meter provides water level and drawdown detection modes. | Applications requiring both manual water level measurements and drawdown indication. |
Need help choosing? Browse our Solinst water level meters or contact Activated Carbon Depot with your expected water depth, well diameter, and access requirements.
Ordering the Solinst Model 104
Solinst part number 115747 includes the Model 104 control unit, connected sonic probe, six AA batteries, plastic disc, and Solinst Field Bag.
This model does not require selecting a graduated tape length. Its 6-foot (1.8-meter) cable connects the sonic probe at the wellhead to the handheld control unit; it is not the measuring-depth limit.
Before ordering, confirm the expected depth to water, well diameter, well-cap access, and any casing changes or obstructions. Contact Activated Carbon Depot to discuss your application and any additional setup requirements.
Solinst 104 Downloads and Instructions
- Download the Solinst Model 104 Sonic Water Level Meter Datasheet (PDF)
- Download the Solinst Model 104 Operating Instructions (PDF)
Review the operating instructions before use, including measurement settings, well setup, temperature compensation, and troubleshooting.
Solinst Model 104 Frequently Asked Questions
The Solinst Model 104 measures static depth to water in suitable wells, piezometers, sounding tubes, and closed pipes. It uses sound rather than a probe lowered to the water surface.
The probe sends a sound pulse down the well and detects the returning echo from the water surface. The control unit calculates depth from the pulse's travel time, using temperature compensation to help account for changes in the speed of sound.
No. The sonic probe stays at the well opening during measurement. You do not lower it to the water surface.
Solinst specifies an operating range of 3–600 m, listed as 9–2,000 ft. The achievable depth depends on well conditions, acoustic interference, temperature conditions, and proper setup.
Water levels shallower than the manufacturer-stated minimum of 3 m (9 ft) are outside its specified operating range. Consider a suitable water-contact meter for shallow measurements.
No. The Model 104 measures acoustically and has no graduated measuring tape. Its 6-foot cable connects the wellhead probe to the control unit.
Yes. The control unit offers selectable imperial and metric measurement units.
Suitability depends on the well's diameter, casing configuration, depth to water, background noise, and acoustic path. Significant casing changes or other sources of interference may require a drop tube or a different measurement method.
Solinst recommends a drop tube for wells larger than 8 inches in diameter. A drop tube may also be needed where significant casing changes or perforated sections interfere with the acoustic signal. Follow Solinst's instructions for tube selection and installation.
No. The disc helps cover the well opening and retain the acoustic pulse. A drop tube is still needed when the well configuration requires one.
Yes. Pump noise, changes in casing diameter, and other internal features can interfere with the returning echo. Appropriate minimum and maximum range settings can help, while some installations require a drop tube.
The Model 104 is designed to measure depth to water. Its temperature compensation supports the acoustic distance calculation; it does not replace a meter designed to measure water temperature.
No. Neither the control unit nor the sonic probe is waterproof. Protect both from immersion and follow the handling instructions.
The Model 104 uses six replaceable AA alkaline batteries. Six AA batteries are included.
Part number 115747 includes the control unit, connected sonic probe with a 6-foot cable, six AA batteries, plastic disc, and Solinst Field Bag.
Yes. A Solinst Field Bag is included with this Model 104 package.
Ways to Contact Us
Activated Carbon Depot
Email: sales@activatedcarbondepot.com
Phone: 949-229-2587
