DHT Spring Tester
Digital Hand Tester

Built to order.

Use the DHT for tension or compression testing applications. Standard pull lengths of 12” can be increased with optional extended rods to up to 18” to test longer parts.

  • Up to 18″ range (12″ standard)
  • Standard 6″ stroke
  • Up to 4″ Ø platforms (2″ Ø standard)
See all features
Customize & Buy

DHT – Digital Hand Tester

Use the DHT for tension or compression testing applications. Standard pull lengths of 12” can be increased with optional extended rods to up to 18” to test longer parts. The Digital Hand Tester has higher resolution force and length to test with greater accuracy than our ECT (Electronic Compression Tester) and CDHT (Compression Digital Hand Tester). In addition, this tester can be upgraded with useful options like the Micro-Length Adjust with length stops or USB / RS 232 ports.

The DHT displays force and length readings on a two-line LED screen in real time as values with indicator bars. Like all of our manually-operated spring testers, the DHT has built-in deflection compensation for accurate readings at all times. Built on a rugged cast aluminum and steel frame, the Digital Hand Tester has a precision rack and pinion drive with adjustments for wear and features convenient hand operation to apply force and adjust length. Lastly, the DHT includes 2 position stop rods, a standard length lock, a rechargeable battery and mechanical overload stops to protect the tester from damage.

Includes Length Deflection Compensation

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.

SDC (Spring Data Collector) Software Demo

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.

Download Free Demo

Force Specifications

Load Cell
Capacity		 Standard Resolution High Resolution*
0-100% FS 0-20% FS 20-100% FS
2 lbf 0.001 lbf 0.0001 lbf 0.001 lbf
907 g 0.2 g 0.02 g 0.2 g
8.9 N 0.002 N 0.0002 N 0.002 N
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

Parts and Accessories

Tester

DescriptionPart Number 
DHT - 2 lbf Digital Hand Tester050-0000-0025-00Get a Quote
DHT - 11 lbf Digital Hand Tester050-0000-0019-00Get a Quote
DHT - 110 lbf Digital Hand Tester050-0000-0020-00Get a Quote
DHT - 750 lbf Digital Hand Tester050-0000-0021-00Get a Quote

Accuracy and Factory Options

DescriptionPart Number 
High Resolution Force (10X Resolution from 0-20% FS)050-0000-0107-00Get a Quote
Digital Length Precision Upgrade (0.0005 Res, ± 0.001 Acc)025-0000-0488-00Get a Quote
Micro Length Adjust with Built-in Stops

Micro Length Adjust with Built-in Stops

Part 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.

025-0000-0407-02Get a Quote
MicroAdjust Wrenchless Stop Assembly025-0000-0676-00Get a Quote
Quick Release Range Adjust Handles (200 lbf Max Load)

Quick Release Range Adjust Handles

Part Number: 025-0000-0412-00

Replace your socket head cap screws with these simple handles for quick and easy range adjusting on your tester. 200 lb maximum load.

025-0000-0412-00Get a Quote
RS232 / USB output050-1000-0064-00Get a Quote
23.200" Support Rods (18" Range)018-0000-0907-03Get a Quote

Accessories

DescriptionPart Number 
Spring Button Platform - 1" Ø (Hardened steel)018-0000-0914-01Get a Quote
Platforms - 4" Ø (Pair for 5/16-18 Mount)

Platforms – 4″ Ø

Part Number: 025-0000-0191-00

For testing larger diameter compression parts.

025-0000-0191-00Get 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.

025-0000-0225-00Get 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

025-0000-0485-00Get a Quote
Set of 2" Spring Platforms (HT Tool Steel, No Hole)025-0000-1597-00Get a Quote
Extension Setup Blocks

Setup Blocks

Part Number: 025-0000-0190-00

For compression / extension length zeroing. 12″ extension zeroing; 10″ compression zeroing.

025-0000-0190-00Get a Quote
Extension Spring Swivel Wire Hook - 2 lb cap (0.030" Ø wire)

Wire Extension Hooks – 2 lb max (0.030″ Ø)

Part Number: 025-0000-0340-05

Medium duty hooks for your extension testing.

025-0000-0340-05Get a Quote
Extension Spring Swivel Wire Hook - 2 lb cap (0.050" Ø wire)

Wire Extension Hooks – 2 lb max (0.050″ Ø)

Part Number: 025-0000-0340-06

Medium duty hooks for your extension testing.

025-0000-0340-06Get a Quote
Pin Extension Hooks

Pin Extension Hooks

Light duty hooks for your extension testing. The above pictures show 025-0000-0250-05 (including the swivel mount).

Part Number Description
025-0000-0250-01 B Pin Extension Hooks – 2 lb max (Fixed Mount)
025-0000-0250-02 B Pin Extension Hooks – 66 lb max (Fixed Mount)
025-0000-0250-03 B Pin Extension Hooks – 110 lb max (Fixed Mount)
025-0000-0250-04 A Pin Extension Hooks Set – 2 / 66 / 110 lb max (Fixed Mount) Comes with protective carrying and storage case.
025-0000-0250-05 A Pin Extension Hooks Set – 2 / 66 / 110 lb max (Swivel Mount) Comes with protective carrying and storage case.
025-0000-0250-04Get a Quote
Wire Extension Hooks - 10 lb max (1/16" Ø wire)

Wire Extension Hooks – 10 lb max (1/16″ Ø wire)

Part Number:025-0000-0340-01

025-0000-0340-01Get a Quote
Wire Extension Hooks - 66 lb max (3/32" Ø wire)

Wire Extension Hooks – 66 lb max (3/32″ Ø wire)

Part Number: 025-0000-0340-02

025-0000-0340-02Get a Quote
Wire Extension Hooks - 110 lb max (1/8" Ø wire)

Wire Extension Hooks – 110 lb max (1/8″ Ø wire)

Part Number: 025-0000-0340-00

025-0000-0340-00Get a Quote
Wire Extension Hook Set - 10 / 66 / 110 lb max. Includes protective carrying and storage case.

Wire Extension Hook Set – 10 / 66 / 110 lb max.

Part Number: 025-0000-0340-03

Wire Extension Hook Set – 10 / 66 / 110 lb max. Includes protective carrying and storage case.

025-0000-0340-03Get a Quote
Wire Extension Hooks - 1,000 lb max (5/16" Ø wire)

Wire Extension Hooks – 1,000 lb max (5/16″ Ø wire)

Part Number: 025-0000-0514-00

025-0000-0514-00Get a Quote
Wire Extension Hooks

Wire Extension Hooks

Part Number: 025-0000-0523-00

Medium duty hooks for extension testing. Protective carrying and storage case included with sets.

Part Number Description
025-0000-0340-01 Wire Extension Hooks – 10 lb max (1/16″ Ø wire)
025-0000-0340-02 Wire Extension Hooks – 66 lb max (3/32″ Ø wire)
025-0000-0340-00 Wire Extension Hooks – 110 lb max (1/8″ Ø wire)
025-0000-0340-03 Wire Extension Hook Set – 10 / 66 / 110 lb max. Includes protective carrying and storage case.
025-0000-0514-00 Wire Extension Hooks – 1,000 lb max (5/16″ Ø wire)
025-0000-0523-00 Extension Hook Set – Pin & Swivel – 10 / 66 / 110 / 1,000 lb
025-0000-0523-00Get a Quote
Machined Extension Hooks

Machined Extension Hooks

Part Number: 025-0000-0181-00

Heavy duty hooks for your extension testing.

Part Number Description
025-0000-0183-00 Machined Extension Hooks – 110 lb max
025-0000-0181-00 Machined Extension Hooks – 750 lb max
025-0000-0183-01 A Machined Extension Hook Set – 110 / 750 lb max. Includes protective carrying and storage case.
025-0000-0181-00Get a Quote
Wire Crimp Pull Fixture - Upper, 1/32 to 7/16 slot width

Wire Crimp Pull Fixture – Upper

Part Number: 025-0000-0271-00

Test your wire crimp’s integrity with LSI’s wire crimp fixtures. The upper pull fixture features 18 slots ranging from 0.031″ to 0.437″ and can accommodate up to #4 gage wire. Choose between 110 and 1,000 lb lower grip fixtures.

025-0000-0271-00Get a Quote
Wire Crimp Grip Fixture - Lower 110 lb

Wire Crimp Pull Fixture – Lower

Part Number: 025-0000-0274-00

Test your wire crimp’s integrity with LSI’s wire crimp fixtures. The upper pull fixture features 18 slots ranging from 0.031″ to 0.437″ and can accommodate up to #4 gage wire. Choose between 110 and 1,000 lb lower grip fixtures.

025-0000-0274-00Get a Quote
Wire Crimp Grip Fixture - Lower 1,000 lb

Wire Crimp Pull Fixture – Lower

Part Number: 025-0000-0274-00

Test your wire crimp’s integrity with LSI’s wire crimp fixtures. The upper pull fixture features 18 slots ranging from 0.031″ to 0.437″ and can accommodate up to #4 gage wire. Choose between 110 and 1,000 lb lower grip fixtures.

025-0000-0272-00Get a Quote
Smooth Jaw Wire Chucks - 100 lb

Wire Chucks

Part Number: 025-0000-0193-00

For extension wire breakage testing: accepts 0.020″ to 0.312″ Ø wire.

025-0000-0193-00Get a Quote
Serrated Jaw Wire Chucks - 200 lb

Wire Chucks

Part Number: 025-0000-0193-01

For extension wire breakage testing: accepts 0.020″ to 0.312″ Ø wire.

025-0000-0193-01Get a Quote
Smooth Jaw Wire Chucks - 400 lb

Wire Chucks

Part Number: 025-0000-0193-02

For extension wire breakage testing: accepts 0.020″ to 0.312″ Ø wire.

025-0000-0193-02Get a Quote
Air Vibration Damping Table

Air Vibration Damping Table

Part 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:

  1. Mount the CDHT, DHT or SDHT onto the table using the four included 1/4-20 x 3/4” bolts.
  2. Turn the three front air valves (clockwise) to the “off” position.
  3. Connect a pneumatic air line.
  4. Turn air valves (counter-clockwise) to pressurize each mount so that the table is not resting directly on the three mounts, and the weight on the table is supported (80 PSI maximum).
  5. Place a leveling instrument on the table and adjust the air pressure equally until the table is level.
025-0000-0288-00Get a Quote
Vibration Damping Pad

Vibration Damping Pad

Part Number: 025-0000-0226-00

Foam Vibration Damping Pad

025-0000-0226-00Get a Quote
5/16-18 M to 10-32 M/F Thread Adapter

Thread Adapters

Part Number: 018-0000-1718-00

Use differently threaded attachments with your Larson tester.

018-0000-1718-00Get a Quote
5/16-18 M to M6 M/F Thread Adapter

Thread Adapters

Part Number: 018-0000-1718-01

Use differently threaded attachments with your Larson tester.

018-0000-1718-01Get a Quote
5/16-18 M to M4 M/F Thread Adapter

Thread Adapters

Part Number: 018-0000-1718-02

Use differently threaded attachments with your Larson tester.

018-0000-1718-02View Product
Dust Cover - 12" Range Rods

Dust Cover

Part Number: 059-1000-0004-00

059-1000-0004-00View Product
Dust Cover - 18" Range Rods

Dust Cover

Part Number: 059-1000-0012-00

059-1000-0012-00Get a Quote
TUL - Twist Under Load

Twist Under Load

Part Number: 050-0000-0099-00

Graduated Markers
The Twist Under Load has indicating marks that will measure the amount of twist in any given spring.

Capacity
From 10 to 2,000 lbs and up to 4″ Ø.

Captivated Ball Bearings
With lubricated ball bearings, this unit will rotate smoothly and with very light force.

Universal Mounting (excluding the Flash 11 & Flash 24)
Will mount to any Larson tester, or any tester with 5/16-18 mounting holes.

050-0000-0099-00Get a Quote
Small Parts Catcher for 2" diameter platforms018-0000-4228-00Get a Quote
Rubber Mounting Foot Upgrade025-0000-1310-00Get a Quote
Solid Height (Coil Bind) Protector - 2" 018-0000-4358-00View Product

Software

DescriptionPart Number 
SSS - Statistical & Spreadsheet Interface Software

Total Spring Inspection
The SSS software can connect to any LSI manual tester, including the DHT and the TST, and virtually any measuring device that can send data via RS232. The SSS can also accept data from the keyboard. By setting up a specific testing method, you can test your springs reliably and repeatedly and generate one comprehensive report.

Click here to view

050-0000-0075-00Get a Quote
Spring Data Collector Software

Force@Length Data at Your Fingertips!
With the Larson Systems’ SDC Software, your spring testing results can be accessed, stored and manipulated as they are generated, giving you complete control of your spring testing data.

Click here to view

050-1000-0060-01Get a Quote

Power Supplies

DescriptionPart Number 
Power Supply, 100-240 VAC 50-60 Hz (USA Plug)025-1000-0396-00Get a Quote
Power Supply, 100-240 VAC 50-60 Hz (International Plugs)025-1000-0396-04Get a Quote