SDHT Spring Tester
Super Digital Hand Tester

  • 2, 11, 22, 66, 110, 200 and 750 lbf load capacities
  • Up to 24″ range and 19″ stroke
  • Standard 0.0005″ length resolution

This demo of our Valve Spring Tester shows some of the great capabilities of our robust hand-operated spring tester line.

SDHT Generation 2

The SDHT is Larson Systems’ top-of-the-line hand operated spring tester. It is available in seven different load capacities, all tuned to the highest precision to excel against your toughest testing requirements.

All Larson Systems spring testers have BUILT-IN DEFLECTION COMPENSATION for accurate readings at all times. Testers without deflection compensation will always have length readings that contain error and this will also limit the benefit of high force resolution.

5 Optional Testing Capabilities That Set the SDHT Apart from Other Spring Testers

  1. Pass Through Testing
  2. Two Point with Rate
  3. Calculated Free Length
  4. Initial Tension
  5. Limit Lights & Full Statistical Analysis

Rugged Construction

Use this tester for compression or extension applications from 2 to 750 lb. Standard pull lengths of 12” can be increased with optional extended rods to up to 24” to test long parts. It has higher resolution force and length to test with greater accuracy.The SDHT comes standard with a two-line backlit LED display of force and length with built-in load cell and frame deflection compensation for accurate readings at all times. It has a rugged cast aluminum and steel frame, precision rack and pinion drive with adjustments for wear and convenient hand operation to apply force and adjust length. Precision Guides for increased accuracy are standard on the SDHT and LSI offers powerful, optional tester software features to make testing easy and productive. It includes Micro Length Adjust with built-in stops, standard length lock, rechargeable battery and mechanical overload stops to protect the tester from damage.

 

5 Incredible Testing Capabilities

1. Pass Through Testing


Test up to two preselected force or length points in one spring deflection without stopping. Pass Through Testing will increase operator testing efficiency with the SDHT.

Rather than deflecting the spring and pressing F1 or F2 to capture each individual test point, Pass Through Testing will capture your two preselected force or length test points in one fluid deflection of the spring and display the data on-screen.  Once the test is complete, you can:

 

  • Press SEND to access the data on a connected computer using our SDC (Spring Data Collector) or SSS (Statistical & Spreadsheet Interface Software) software programs, or…
  • Press STORE to save both test points in tester memory, or…
  • Press SEND to print to a connected printer


2. Two Point with Rate

Test two points with spring rate calculation in one deflection of the spring.


2 Point With Rate is a tester software option that allows you to calculate the rate (or spring constant) between two points. To use this feature, press the Test Mode button to enter 2 Point With Rate mode. Set your first test point by using the tester’s force and length readings as a guide and pressing the F1 button. Set the second test point using the same method. When both test points are set the tester automatically calculates and displays the rate as shown. This is all accomplished in just one deflection of the spring!

2 Point with Rate is a tester software feature. A PC is not needed for this software.
Click for Print Samples


3. Calculated Free Length (includes 2 Point with Rate)

Calculate the free length of a compression spring.


Calculated Free Length is a tester software option that allows you to calculate the free length of a compression spring. To use this feature, press the Test Mode button to enter 2 Point with Free Length mode. Set your first test point by using the tester’s force and length readings as a guide and pressing the F1 button. Set the second test point using the same method. When both test points are set the tester automatically calculates and displays the rate and the free length as shown.

Calculated Free Length is a tester software feature. A PC is not needed for this software.


4. Initial Tension (includes 2 Point with Rate)

Calculate the initial tension of an extension spring.


Initial Tension is a tester software option that allows you to calculate the force required to start separating the coils of an extension spring. To use this feature, press the Test Mode button to enter 2 Point with Initial Tension mode. Find the unloaded length of the spring by using the tester’s force and length readings as a guide and pressing the F1 button. Then set the first and second test point using the same method. When both test points have been set, the tester automatically calculates and displays the rate and initial tension as shown.

Initial Tension is a tester software feature. A PC is not needed for this software.


5. Limit Lights & Full Statistical Analysis

Part sorting using bright LED limit lights for good / bad parts and a statistical summary printout that includes a histogram and data run chart.

Limit LightsThis software option lets the user program the limit lights to make sorting reliable and efficient. This option also uses the programmed limits to enable the Mean, Standard Deviation, Range, Range Chart, Histogram, Cp and Cpk statistical printed outputs. Limit Lights and Full Statistics Analysis is a tester software feature. A PC is not needed for this software.

Click here for print samples


Includes Length Deflection Compensation

What is length deflection compensation?
All force/lengh 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/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 Software Demo

Try our software for “Spring Testing Data at Your Fingertips”. With Larson System’s SDC 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.

Free Demo

Force Specifications

Load Cell
Capacity
Standard Resolution
0-20% FS 20-100% FS
2 lb 0.00002 lb 0.0002 lb
907 g 0.01 g 0.1 g
8.9 N 0.0001 N 0.001 N
11 lb 0.0002 lb 0.002 lb
5 kg 0.1 g 1 g
49 N 0.001 N 0.01 N
22 lb 0.0005 lb 0.005 lb
10 kg 0.2 g 2 g
98 N 0.002 N 0.02 N
66 lb 0.001 lb 0.01 lb
30 kg 0.5 g 5 g
294 N 0.005 N 0.05 N
110 lb 0.002 lb 0.02 lb
50 kg 0.001 kg 0.01 kg
489 N 0.01 N 0.1 N
200 lb 0.005 lb 0.05 lb
91 kg 0.002 kg 0.02 kg
890 N 0.02 N 0.2 N
750 lb 0.02 lb 0.2 lb
340 kg 0.01 kg 0.1 kg
3,336 N 0.1 N 1 N
Accuracy = ± Full Scale Resolution x 2

Parts and Accessories

Testers

DescriptionPart Number 
SDHT - Super Digital Hand Tester 2 lb - (2" Platform)050-0000-0043-00Get a Quote
SDHT - Super Digital Hand Tester 11 lb - (2" Platform)050-0000-0044-00Get a Quote
SDHT - Super Digital Hand Tester 22 lb - (2" Platform)050-0000-0087-00Get a Quote
SDHT - Super Digital Hand Tester 66 lb - (2.375" Platform)050-0000-0076-00Get a Quote
SDHT - Super Digital Hand Tester 110 lb - (2.375" Platform)050-0000-0045-00Get a Quote
SDHT - Super Digital Hand Tester 200 lb - (2.375" Platform)050-0000-0077-00Get a Quote
SDHT - Super Digital Hand Tester 750 lb - (2.375" Platform)050-0000-0046-00Get a Quote

Factory Options

DescriptionPart Number 
Quick Release Range Adjust Handles (200 lb Max Load)025-0000-0412-00Get a Quote
Extended Range Rods to 18"018-0000-1563-01Get a Quote
Extended Range Rods to 24"018-0000-1563-04Get a Quote
Extended Stroke to 19"025-0000-0308-00Get a Quote
Extended Stroke to 19" with 0.312" Ø Thru-Hole025-0000-0308-01Get a Quote
MicroAdjust Wrenchless Stop Assembly025-0000-0676-00Get a Quote

Tester Software Options

DescriptionPart Number 
Pass Through Testing050-0000-0067-00Get a Quote
2 Point with Rate050-0000-0072-00Get a Quote
Calculated Free Length (includes 2 Point with Rate)050-1000-0040-00Get a Quote
Initial Tension (includes 2 Point with Rate)050-1000-0041-00Get a Quote
Limit Lights & Full Statistical Analysis050-1000-0073-00Get a Quote

Computer Software

DescriptionPart Number 
SSS - Statistical & Spreadsheet Interface Software050-0000-0075-00Get a Quote

Accessories

DescriptionPart Number 
Thru-Rod Support Kit (1/16 to 1/8" Ø x 6")025-0000-0225-00Get a Quote
Thru-Rod Accessory Kit (1/16 to 1/4" Ø)025-0000-0424-00Get a Quote
4" Ø Platform / Thru-Rod Support Kit (1/16 to 11/16" Ø ID x 8")025-0000-0485-00Get a Quote
Platforms - 4" Ø025-0000-0191-00Get a Quote
Setup Blocks025-0000-0190-00Get a Quote
Wire Extension Hooks - 2 lb max (0.030" Ø)025-0000-0340-05Get a Quote
Wire Extension Hooks - 2 lb max (0.050" Ø)025-0000-0340-06Get a Quote
Extension Spring Swivel Hook Set - 10/66/110 lb025-0000-0340-03Get a Quote
Pin Extension Hooks025-0000-0250-04Get a Quote
Wire Extension Hooks025-0000-0523-00Get a Quote
Machined Extension Hooks025-0000-0181-00Get a Quote
Wire Crimp Pull Fixture - Upper025-0000-0271-00Get a Quote
Wire Crimp Grip Fixture - Lower 110 lb025-0000-0274-00Get a Quote
Wire Crimp Grip Fixture - Lower 1,000 lb025-0000-0272-00Get a Quote
Smooth Jaw Wire Chucks - 100 lb025-0000-0193-00Get a Quote
Serrated Jaw Wire Chucks - 200 lb025-0000-0193-01Get a Quote
Smooth Jaw Wire Chucks - 400 lb025-0000-0193-02Get a Quote
Air Vibration Damping Table025-0000-0288-00Get a Quote
Vibration Damping Pad025-0000-0226-00Get a Quote
5/16-18 M to 10-32 M/F Thread Adapter018-0000-1718-00Get a Quote
5/16-18 M to M6 M/F Thread Adapter018-0000-1718-01Get a Quote
5/16-18 M to M4 M/F Thread Adapter018-0000-1718-02Get a Quote
Dust Cover (Standard 12" Range Rods)059-1000-0004-00Get a Quote
Dust Cover (18" Range Rods)059-1000-0012-00Get a Quote
TUL - Twist Under Load050-0000-0099-00Get 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 - 2.375" 018-0000-4358-01View Product
Solid Height (Coil Bind) Protector - 2" 018-0000-4358-01View Product

Printer & Connectivity Options

DescriptionPart Number 
Inkjet Printer (Includes Cable / Adapter 025-0000-0458-00)025-0000-0464-00Get a Quote
RS 232 to Parallel Printer Cable / Adapter025-0000-0458-00Get a Quote
SSS - PC Statistical & Spreadsheet Interface Software050-0000-0075-00Get a Quote

Power Supplies

DescriptionPart Number 
Power Supply - USA (115 VAC)025-1000-0396-00Get a Quote
Power Supply - International (100-240 VAC 50-60 Hz)025-1000-0396-04Get a Quote