Solinst Model 101D Water Level and Drawdown Meter
The Solinst Model 101D is a manual water level meter that measures depth to water and provides an audible and visual warning when a falling water level drops below a selected probe position. Its switchable Water Level and DrawDown modes support routine groundwater measurements, low-flow sampling, well purging, pumping tests, and dewatering applications.
The 101D combines a P7 probe with laser-marked PVDF flat tape and a portable reel. Choose an imperial LM2 configuration from 100 to 1,000 ft or a metric LM3 configuration from 30 to 300 m using the options on this page.
How Water Level and Drawdown Modes Work
In Water Level mode, the light and buzzer activate when the probe’s zero measurement point reaches water. Read the tape at your reference point to determine depth to water.
To monitor a drawdown threshold, use Water Level mode to position the probe at your chosen depth below the water surface, then switch to DrawDown mode. The light and buzzer activate when the falling water level exposes the probe’s detection point to air.
The 101D does not automatically record readings or calculate drawdown. Determine drawdown by subtracting the initial depth-to-water reading from a subsequent reading taken from the same reference point.
Optional Automatic Pump Control
Used on its own, the 101D provides an audible and visual indication for the operator. With an optional DrawDown Link Cable Assembly and a compatible Solinst Model 410 Mk5 Peristaltic Pump, it can enable automatic pump control based on water level.
The DrawDown Link Cable Assembly and pump are sold separately. Confirm hardware compatibility before ordering components for an automated pumping setup.
P7 Probe and Laser-Marked Flat Tape
The P7 probe is 16 mm (5/8 in) in diameter and 137 mm (5.38 in) long. It is submersible to the full length of the meter’s tape. The sensor near the probe tip provides a consistent measurement point, while a protective shroud helps protect the probe.
The 10 mm (3/8 in) wide PVDF flat tape has permanent laser markings every 1/100 ft on LM2 imperial models or every millimeter on LM3 metric models. These increments describe the spacing of the markings, rather than a separate statement of overall measurement accuracy.
The reel includes a carrying handle, probe holder, brake, accessible 9V battery drawer, sensitivity control, mode switch, light, buzzer, and battery test button. The included tape guide helps protect the tape from rough casing edges and provides a consistent measurement reference.
Applications
- Measuring depth to water in wells, boreholes, standpipes, and tanks
- Monitoring a selected drawdown threshold during low-flow groundwater sampling
- Checking falling water levels during well development and purging
- Taking manual readings during pumping and step-drawdown tests
- Monitoring water levels during dewatering operations
- Supporting automatic pump control with the optional link cable and a compatible Model 410 Mk5 pump
Select the tape length and measurement units that match your monitoring requirements. For configuration assistance or pricing on multiple meters, contact Activated Carbon Depot.
Solinst Model 101D Technical Specifications
| Specification | Details |
|---|---|
| Measurement functions | Manual depth-to-water measurement and drawdown threshold detection |
| Operating modes | Switchable Water Level and DrawDown modes |
| Water Level indication | Light and buzzer activate when the probe’s zero measurement point reaches water |
| DrawDown indication | Light and buzzer activate when the probe is exposed to air |
| Probe | Solinst P7 probe with protective shroud |
| Probe dimensions | 16 mm diameter × 137 mm long (5/8 in × 5.38 in) |
| Probe weight | Approximately 128 g (4.5 oz) |
| Probe submergence | Submersible to the full length of the meter’s tape |
| Tape material and width | Laser-marked PVDF flat tape, 10 mm (3/8 in) wide |
| LM2 imperial graduations | Feet and tenths, with markings every 1/100 ft |
| LM3 metric graduations | Meters and centimeters, with markings every millimeter |
| Imperial lengths listed on this page | 100, 200, 300, 500, 750, and 1,000 ft |
| Metric lengths listed on this page | 30, 60, 100, 150, 250, and 300 m |
| Power supply | 9V battery in an accessible battery drawer |
| Reel features | Carrying handle, probe holder, brake, tape guide, sensitivity control, mode switch, and battery test button |
| Reel protection rating | IP64: dust-tight and protected against splashing water; the reel is not submersible |
| Reel operating temperature | -20°C to +50°C |
| Submerged tape/probe operating temperature | -20°C to +80°C |
| Wetted materials | PVDF, Santoprene, Delrin, Viton, and 316 stainless steel |
| Automatic data logging | No; readings are taken and recorded manually |
Tape graduation spacing is not the same as overall measurement accuracy. Use a consistent reference point when comparing water level readings. When using the tape guide, apply the reference-point offset shown on the guide.
Available Solinst 101D Models and Part Numbers
All configurations listed below include the P7 probe and switchable Water Level and DrawDown modes. Choose your tape length and measurement units before ordering.
LM2 Imperial Models — Feet
LM2 tape is marked in feet and tenths, with graduations every 1/100 ft.
| Tape Length | Configuration | Solinst Part Number / SKU |
|---|---|---|
| 100 ft | 101D / P7 / LM2 | 114115 |
| 200 ft | 101D / P7 / LM2 | 114116 |
| 300 ft | 101D / P7 / LM2 | 114117 |
| 500 ft | 101D / P7 / LM2 | 114118 |
| 750 ft | 101D / P7 / LM2 | 114119 |
| 1,000 ft | 101D / P7 / LM2 | 114120 |
LM3 Metric Models — Meters
LM3 tape is marked in meters and centimeters, with graduations every millimeter.
| Tape Length | Configuration | Solinst Part Number / SKU |
|---|---|---|
| 30 m | 101D / P7 / LM3 | 114121 |
| 60 m | 101D / P7 / LM3 | 114122 |
| 100 m | 101D / P7 / LM3 | 114123 |
| 150 m | 101D / P7 / LM3 | 114124 |
| 250 m | 101D / P7 / LM3 | 114125 |
| 300 m | 101D / P7 / LM3 | 114126 |
Before Ordering
- Select LM2 for readings in feet or LM3 for readings in meters.
- Choose a tape length that reaches your deepest expected water level or planned drawdown monitoring position.
- Confirm that the 16 mm (5/8 in) diameter P7 probe can pass through the available opening, including any restrictions around installed equipment.
- Match the selected variant and part number to your purchase order.
Imperial and metric configurations are separate tape options. For requirements beyond the lengths listed here, contact Activated Carbon Depot to confirm configuration availability and pricing.
Which Solinst Water Level Meter Should You Choose?
Choose a meter based on whether you need drawdown threshold detection, the available probe clearance, and your preferred tape or cable style.
| Model | Measurement Functions | Tape or Cable | When to Choose It |
|---|---|---|---|
| Solinst 101D | Manual depth-to-water measurement and selectable drawdown threshold detection; optional pump control with compatible equipment | Laser-marked PVDF flat tape with P7 probe | When you need water level readings and an alarm at a selected depth during pumping, purging, or sampling |
| Solinst 101 P7 | Manual depth-to-water measurement | Laser-marked PVDF flat tape with P7 probe | When you want the P7 probe and laser-marked flat tape for water level readings without a dedicated drawdown mode |
| Solinst 101 P2 | Manual depth-to-water measurement | Heat-embossed polyethylene flat tape with P2 probe | When you prefer a conventional flat-tape meter with an easy-to-repair P2 probe |
| Solinst 102 P10 | Manual depth-to-water measurement | Laser-marked narrow coaxial cable with a 10 mm diameter P10 probe | When a smaller probe and narrow cable are needed for restricted access or measurements alongside installed equipment |
What Makes the 101D Different from the 101 P7?
The 101D uses the same P7 probe and laser-marked flat tape style as the 101 P7, with the addition of a Water Level/DrawDown mode switch. In Water Level mode, the light and buzzer activate when the probe reaches water. In DrawDown mode, they activate when falling water exposes the probe’s detection point to air.
The drawdown alarm identifies when water crosses the selected probe position. The meter does not automatically calculate drawdown or record readings. Calculate drawdown by comparing depth-to-water readings taken from the same reference point.
Can the 101D Control a Pump?
The meter alone provides an audible and visual indication and does not control a pump. An optional DrawDown Link Cable Assembly allows connection to a compatible Solinst Model 410 Mk5 Peristaltic Pump for automatic pump control based on water level. The link cable and pump are sold separately; confirm hardware compatibility before ordering.
Which Model Is Better for Narrow Openings?
The 102 P10 has a 10 mm diameter probe, compared with the 101D’s 16 mm diameter P7 probe. Consider the 102 P10 when available clearance requires a smaller probe and narrow cable. Check the full measurement path, including restrictions around pumps and tubing, before selecting a meter.
What’s Included with the Solinst 101D?
- Assembled Solinst Model 101D Water Level DrawDown Meter with reel, P7 probe, and the selected tape length and measurement units
- 9V battery
- Tape guide
Sold Separately
A carrying case is sold separately and is not included with the meter. Replacement parts and additional accessories are also sold separately unless explicitly listed in your order.
Before ordering, confirm your selected tape length, LM2 imperial or LM3 metric graduations, and Solinst part number.
Solinst 101D Frequently Asked Questions
The Solinst 101D measures depth to water manually and provides drawdown threshold detection. Its Water Level mode signals when the probe reaches water, while DrawDown mode signals when a falling water level exposes the probe to air.
Position the probe at your chosen monitoring depth while in Water Level mode, then switch to DrawDown mode. The light and buzzer activate when the water level falls below the probe's detection point, exposing it to air.
No. Calculate drawdown by subtracting the initial depth-to-water reading from the subsequent reading, using the same reference point. DrawDown mode provides an alarm when water falls below the selected probe position.
Both use a P7 probe and laser-marked PVDF flat tape. The 101D adds a switchable DrawDown mode that signals when the probe is exposed to air. The standard 101 P7 signals when its probe reaches water.
Yes. The probe can be positioned at a selected drawdown threshold to alert the operator when water falls below that point during sampling. Follow your project's sampling procedures when selecting the threshold and adjusting pumping rates.
The meter alone provides an audible and visual indication and does not control a pump. With an optional DrawDown Link Cable Assembly and a compatible Solinst Model 410 Mk5 Peristaltic Pump, it can enable automatic pump control based on water level. The link cable and pump are sold separately.
Imperial LM2 models are available in 100, 200, 300, 500, 750, and 1,000 ft lengths. Metric LM3 models are available in 30, 60, 100, 150, 250, and 300 m lengths.
LM2 tape is marked in feet and tenths, with graduations every 1/100 ft. LM3 tape is marked in meters and centimeters, with graduations every millimeter. They are separate tape configurations; select the units required for your work.
No. Graduation spacing describes the distance between tape markings. Overall measurement accuracy is a separate specification. Consistent reference points and proper measurement technique also affect your readings.
The P7 probe is 16 mm (5/8 in) in diameter and 137 mm (5.38 in) long. Check that it can pass through the available opening and any restrictions around installed pumps, tubing, or other equipment.
Yes. The P7 probe is submersible to the full length of the meter's tape. This applies to the probe; the reel is not submersible.
No. The 101D is a manual instrument. Read the tape at your reference point and record the measurement yourself. It does not provide automatic data logging.
The tape guide changes the measurement reference point relative to the top of the well casing. Apply the offset indicated on your guide when reporting measurements relative to the casing.
The package includes the assembled meter with reel, P7 probe, selected tape configuration, a 9V battery, and a tape guide.
Solinst 101D PDF Downloads
Ways to Contact Us
Activated Carbon Depot
Email: sales@activatedcarbondepot.com
Phone: 949-229-2587
