Solinst Model 105 Water Level and Casing Depth Meter

Overview

The Solinst Model 105 Water Level and Casing Depth Meter is a field-deployable, dual-function geotechnical measurement instrument engineered for precision detection of both metal well casing endpoints (top and bottom) and total borehole depth in a single deployment. It operates on the principle of magnetic proximity sensing—utilizing a high-coercivity permanent magnet assembly integrated into a compact 316 stainless steel probe—to detect ferromagnetic well casings without physical contact. Simultaneously, its mechanical piston-actuated bottom-contact mechanism provides unambiguous confirmation of total depth via a distinct, time-delayed acoustic-optical signal. Designed for rugged field use in hydrogeological site characterization, well construction verification, and regulatory compliance monitoring, the Model 105 delivers repeatable, operator-independent measurements under ambient and submerged conditions across a wide thermal range.

Key Features

• Dual-mode stainless steel probe with integrated high-strength neodymium magnet for reliable casing top/bottom detection and mechanical piston switch for definitive bottom-of-hole confirmation
• Laser-etched, flat-profile measuring tape available in two calibrated scales: LM2 (feet & tenths, marked at 0.01-ft intervals) and LM3 (meters & centimeters, marked at 1-mm intervals)
• Modular reel system supporting tape lengths from 30 m to 600 m (100 ft to 2000 ft), with quick-release spool design for tape replacement in the field
• IP64-rated reel housing with integrated battery test button and slide-out 9V alkaline battery compartment for rapid power verification and maintenance
• Probe rated for continuous submersion up to 500 m (1650 ft) water column pressure; operational temperature range: −20°C to +80°C (probe and tape), −20°C to +50°C (reel)
• Construction materials fully compatible with groundwater sampling protocols: PVDF-coated tape guide, Santoprene seals, Delrin structural components, Viton O-rings, and 316 stainless steel probe body
• Three-year limited warranty covering probe electronics, reel mechanics, and tape calibration integrity

Sample Compatibility & Compliance

The Model 105 is validated for use with standard steel, stainless steel, and galvanized well casings commonly installed in environmental monitoring wells, municipal supply wells, and geotechnical observation points. Its non-invasive magnetic sensing eliminates risk of casing damage during repeated surveys. The device complies with ASTM D5092–22 (“Standard Practice for Design and Installation of Ground-Water Monitoring Wells”) for casing depth verification and supports GLP-aligned data collection workflows when paired with Solinst’s certified field log templates. While not intrinsically rated for hazardous locations, its low-voltage DC circuitry (9V battery-powered) and absence of spark-prone components meet general safety requirements for Class I, Division 2 environments per CSA C22.2 No. 157. All materials contacting water or soil are REACH-compliant and free of intentionally added PFAS compounds.

Software & Data Management

The Model 105 is a standalone, hardware-only instrument requiring no software interface or firmware updates. Depth readings are recorded manually in field logs with traceable metadata—including date, operator ID, well tag, tape serial number, and ambient conditions—as required under EPA Method 533 and ISO 5667-3 for groundwater quality sampling. Optional Solinst Field Logbook kits provide pre-formatted, carbonless triplicate sheets with dedicated fields for top-of-casing, bottom-of-casing, and total depth entries, enabling direct audit trail generation for regulatory submissions (e.g., US EPA Region 10 Well Completion Reports or Environment Canada EDRMS). Battery voltage verification prior to each measurement ensures consistent signal amplitude and alarm reliability—critical for Part 11–aligned data integrity in regulated settings.

Applications

• Verification of casing installation depth during new well construction per provincial/territorial groundwater regulations (e.g., Ontario Regulation 903/90)
• Pre- and post-hydraulic fracturing (water-flood or stimulation) casing integrity assessment
• Positioning of inflatable packers, slotted liners, and isolation barriers within multi-zone monitoring wells
• Baseline depth profiling prior to abandonment or decommissioning of legacy wells (per API RP 90G and CSA Z246.1)
• Periodic inspection of casing corrosion or deformation in long-term observation networks
• Calibration reference for pressure transducer deployments and sonic logging systems

FAQ

Can the Model 105 detect non-metallic casings such as PVC or fiberglass?
No. The instrument relies exclusively on magnetic coupling and is designed only for ferromagnetic well casings (steel, stainless steel, galvanized pipe). Non-magnetic materials require alternative methods such as optical tape readers or ultrasonic depth gauges.
Is the measuring tape resistant to chemical exposure in contaminated groundwater?
Yes. The PVDF-coated LM2/LM3 tapes exhibit broad resistance to hydrocarbons, chlorinated solvents, acids (pH 2–12), and oxidants encountered in brownfield sites, per ASTM D543–20 testing protocols.
How is measurement uncertainty quantified for regulatory reporting?
Systematic uncertainty is ±0.06 m (±0.2 ft) per NIST-traceable calibration certificate included with each tape reel. Operator-induced parallax error is mitigated by the tape’s high-contrast laser etching and rigid guide channel geometry.
Does Solinst provide calibration services for the Model 105?
Yes. Annual recalibration—including probe sensitivity verification, tape length validation against master standards, and alarm threshold revalidation—is available through Solinst’s Burlington, ON service center with ISO/IEC 17025-accredited procedures.
Can the same probe be used interchangeably across different tape reels?
Yes. The probe connects via standardized 4-pin waterproof connector and is fully compatible with all Solinst Model 105 reel configurations, regardless of tape length or scale unit.