Larson Systems Inc.
Manufacturing Expert Spring Testing Solutions Since 1979
Built to order.
The CDHT (Compression Digital Hand Tester) can accommodate larger springs (up to 6” tall) and test with greater accuracy than our ECT (Electronic Compression Tester).
The CDHT (Compression Digital Hand Tester) can accommodate larger springs – up to 6” tall – and test with greater accuracy than our ECT (Electronic Compression Tester). In addition, this tester can be upgraded with useful options like the Micro-Length Adjust with length stop, USB / RS 232 ports, as well as single or double length stop rods. Force and length readings are displayed on a two-line LED screen in real time as values with indicator bars. As is the case with all our manual testers, the Compression Digital Hand Tester has built-in deflection compensation for accurate readings at all times. The CDHT is built on a rugged cast aluminum and steel frame, moves on a precision rack and pinion drive with adjustments for wear, and features convenient hand operation to apply force and adjust length. A standard length lock and mechanical overload stops help protect the tester from damage.
Micro Length Adjust
Make extremely fine length adjustments and utilize two rigid compression stops built right into the assembly (the hand operating lever has been removed in this photo).
LED Force / Length Display
Two-line LED display of force and length with indicator bars featuring built-in deflection compensation for accurate readings at all times.
CDHT Back View
Optional RS 232 / USB Data Output ports sit above the power supply input on the back of the tester.
What is length deflection compensation?
All force/length testing devices, regardless of manufacturer, have additional deflection by the load cell and tester frame which occurs as the spring is loaded. If you buy or use a tester without deflection compensation, measurements might include significant length errors.
Spring deflection, also known as spring travel or motion, is the action of a compression spring compressing (being pushed), an extension spring extending (being pulled), or a torsion spring winding (being twisted) when a load is applied or released. This is one characteristic (spring deflection) that is measured by a Larson Systems Spring Tester.
Larson Systems has built-in Length Deflection Compensation so that the user does not have to calculate and apply length corrections. Most competitors do not have length deflection compensation.
With a Larson Systems product, forget about calculating load cell and frame deflection when testing, we’ve got you covered.
Try our software for “Spring Testing Data at Your Fingertips”. With Larson System’s SDC (Spring Data Collector) Software, your spring testing data can be accessed, stored and manipulated as it is generated. Store specifications for different parts, load a set of parameters and clearly see which springs are out of spec using the on-screen graphical representation of the testing results. Save and print results or open the results file in Microsoft Excel. You have complete control of your testing data.
| Load Cell Capacity |
Standard Resolution | High Resolution* | |
| 0-100% FS | 0-20% FS | 20-100% FS | |
| 11 lbf | 0.005 lbf | 0.0005 lbf | 0.005 lbf |
| 5 kg | 0.002 kg | 0.0002 kg | 0.002 kg |
| 49 N | 0.02 N | 0.002 N | 0.02 N |
| 110 lbf | 0.05 lbf | 0.005 lbf | 0.05 lbf |
| 50 kg | 0.02 kg | 0.002 kg | 0.02 kg |
| 489 N | 0.2 N | 0.02 N | 0.2 N |
| 750 lbf | 0.5 lbf | 0.05 lbf | 0.5 lbf |
| 340 kg | 0.2 kg | 0.02 kg | 0.2 kg |
| 3,336 N | 2 N | 0.2 N | 2 N |
| Accuracy = ± Full Scale Resolution x 2 *Requires High Resolution Force option 050-0000-0107-00 |
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| Description | Part Number | |
|---|---|---|
| CDHT - 11 lbf Compression Digital Hand Tester | 050-0000-0055-00 | Get a Quote |
| CDHT - 110 lbf Compression Digital Hand Tester | 050-0000-0056-00 | Get a Quote |
| CDHT - 750 lbf Compression Digital Hand Tester | 050-0000-0057-00 | Get a Quote |
| Description | Part Number | |
|---|---|---|
| High Resolution Force (10X Resolution from 0-20% FS), DHT | 050-0000-0107-00 | Get a Quote |
| Digital Length Precision Upgrade (0.0005 Res, ± 0.001 Acc) | 025-0000-0488-00 | Get a Quote |
| Description | Part Number | |
|---|---|---|
Micro Length Adjust with Built-in Stops (CDHT, DHT)
Micro Length Adjust with Built-in StopsPart Number: 025-0000-0407-02 Make extremely accurate length adjustments, as well as utilize two extremely rigid compression / extension stops built right in to the assembly. | 025-0000-0407-02 | Get a Quote |
| MicroAdjust Wrenchless Stop Assembly | 025-0000-0676-00 | Get a Quote |
| RS232 / USB output, DHT Family | 050-1000-0064-00 | Get a Quote |
| Description | Part Number | |
|---|---|---|
| Solid Height (Coil Bind) Protection Plate - 2" Ø platorms | 018-0000-4358-00 | View Product |
Platforms - 4" Ø (Pair for 5/16-18 Mount)
Platforms – 4″ ØPart Number: 025-0000-0191-00 A For testing larger diameter compression parts. | 025-0000-0191-00 | Get a Quote |
Thru-Rod Support Kit (1/16 to 1/8" Ø x 4")
Thru-Rod Support Kit (1/16 to 1/8″ Ø x 4″)Part Number: 025-0000-0225-00 Includes rods: 1/16, 3/32 & 1/8″ Ø x 4″ long, accompanying plates with matching holes, as well as upper and lower plates without holes. | 025-0000-0225-00 | Get a Quote |
4" Ø Platform / Thru-Rod Support Kit (1/16 to 11/16" Ø ID x 8")4″ Ø Platform / Thru-Rod Support Kit (1/16 to 11/16″ Ø ID x 8″)
Part Number: 025-0000-0485-00 This kit is more flexible than other thru-rod options and can accommodate larger thru-rods. In addition, springs up to 4″ in diameter can be tested with the over-size platforms. Includes rods: 1/16″ to 11/16″ x 8″ long, and accompanying plates with matching holes. 4″ Ø plate can double for testing springs with larger diameter. NOTE: Deflection compensation is calibrated at the center of the platforms. The length error would vary depending on the load and the location of the load. A centered load is always best and will read accurately, to within ± 0.001″ (0.025 mm) of the actual length. A large off-center load near the edge of the extended platform may be off by up to 0.008″ (0.2 mm). Installation & Use 
| 025-0000-0485-00 | Get a Quote |
| Set of 2" Spring Platforms (HT Tool Steel, No Hole) | 025-0000-1597-00 | Get a Quote |
Single Stop Rod
Single Stop RodPart Number: 025-0000-0293-00 One compression test stop only. | 025-0000-0293-00 | Get a Quote |
Double Stop Rods
Double Stop RodsPart Number: 025-0000-0333-00 Two compression test stops, or one compression test stop and one extension test stop. | 025-0000-0333-00 | Get a Quote |
NiCad Rechargeable Battery (4-8 hr life)
NiCad Rechargeable BatteryPart Number: 025-1000-0654-00 Add an internal rechargeable battery for easy portability. A fully charged battery lasts approximately 8 hours. | 025-0000-0294-00 | Get a Quote |
Dust Cover - ECT, CDHT, CDHT w/Microadjust
Dust CoverPart Number: 059-1000-0026-00 | 059-1000-0026-00 | Get a Quote |
Vibration Damping Pad
Vibration Damping PadPart Number: 025-0000-0226-00 Foam Vibration Damping Pad | 025-0000-0226-00 | Get a Quote |
Air Vibration Damping Table
Air Vibration Damping TablePart Number: 025-0000-0288-00 The Air Vibration Damping Table allows you to make very accurate force measurements in normal industrial environments that have floor or building transmitted vibrations. These vibrations may be induced by industrial equipment, local car, truck or rail traffic and in some cases by people walking by. The Air Vibration Damping Table reduces the magnitude of vibration by 10 to 100 times, making it possible to accurately measure forces at very light loads in environments that would otherwise be impossible. The table should be considered for applications with forces less than 10 lb and is highly recommended for applications with forces less than 2 lb. Air Vibration Damping Table Setup:
| 025-0000-0288-00 | Get a Quote |
| Rubber Mounting Foot Upgrade | 025-0000-1310-00 | Get a Quote |
| Description | Part Number | |
|---|---|---|
| SSS - Statistical & Spreadsheet Interface Software | 050-0000-0075-00 | View SSS Product |
| Spring Data Collector Software (for use with DHT family testers) | 050-1000-0060-01 | View SDC Product |
| Description | Part Number | |
|---|---|---|
| Power Supply, 100-240 VAC 50-60 Hz (USA Plug) | 025-1000-0396-00 | View SSS Product |
| Power Supply, 100-240 VAC 50-60 Hz (International Plugs) | 025-1000-0396-04 | View SDC Product |
