FEDERAL 432 SERIES EAS-2348 GAGING AMPLIFIER, EHE-1048 LVDT GAGE HEAD w/ MANUAL

Description

NO OVERSEAS/INTERNATIONAL BIDS!!!! Sale is intended for the U.S.A only.
NOTE: Please contact me for a shipping rate quote if you live in Alaska or Hawaii
.
I retired (5) years ago after spending the majority of my career working in testing and calibration labs and relocated to the northeast.  I wrote calibration procedures and was the calibration procedure release focal for the largest aerospace manufacture in the U.S.A. My main area of expertise was in dimensional metrology. I also participated in writing many ASME B89 dimensional metrology standards.
I acquired this item used a number of years ago with the intent of possibly opening my own calibration laboratory someday. I have never previously used it. It has been kept in storage since then.
Based upon my years of experience with electronic gaging amplifiers (and audio amplifiers) in general, I have discovered a number of common failure modes. These include carbon composition resistors going up in value, electrolytic capacitors going bad, dirty/noisy potentiometers, and connectors, sockets, switches that need cleaning. I also performed some additional preventative maintenance measures.
The following work was performed on this item:
1.)
Replaced (19) carbon composition resistors with carbon film resistors on EPC1215 oscillator pc board.
2.)
Replaced (3) electrolytic capacitors on EPC1215 oscillator pc board with newer Nichicon capacitors.
3.)
Installed (2) 8 pin IC sockets on EPC1215 oscillator board.
4.) On oscillator pc board, set oscillator to 5kHz (within factory spec +/- 200Hz) (using Leader LDC-823S Digital Frequency Counter) and output to 1.00 V (using Keithley 177 Digital Multimeter).
5.) Checked Bourns (wirewound) zeroing potentiometers for erratic operation with a Keithley Digital Multimeter. Repair, clean or replace, as necessary.
6.) Installed (2) Bourns 200 ohm potentiometers.
7.) Clean and lubricate TRW connectors and 8 pin sockets.
8.) Cleaned knobs.
9.) Painted top cover.
10.)
a. Set front panel “CAL” “A” and “B” (200 ohm) potentiometers to middle of the range.
NOTE: Since this is a digital electronic gaging amplifier later generation EPC-1744 motherboard it does not have any R13-R16 resistors or trim-pots normally associated with INCH and MM scales.
b. Using the calibration process noted below (and a GenRad 1433-B Decade Resistor box), I selected and increased the values of the  resistors in series with the 200 ohm potentiometers to make it possible to get the “CAL” A and B gain adjustment closer to mid-point. Thus allowing more range of adjustment of the “CAL” “A” and “B” (200 ohm) potentiometers during subsequent calibrations or replacement of the gage head.
I performed a “functional test” only of the amplifier.
1.)
Depressing the gage head, I was able to deflect the meter moment from left to right of full scale. (NOTE: For purposes of the photos, I simply used the reversing switch on the electronic amplifier.)
2.)
Using a Boeckeler (20 millionths) micrometer head, I was able to perform a calibration and adjustment of the “CAL A” and CAL B” gain potentiometers on the amplifier on the +/-.010” range (per the instruction manual).
NOTE: Normally the scale accuracies on electronic gaging amplifiers are closely correlated so that when you change from one range to another the accuracy will remain within acceptable limits. I decided however to be sure and performed additional checks on the +/-.002” and +/-.001” scales using the Boeckeler micrometer head.
NOTE: I do not have standards to provide a N.I.S.T. traceable calibration/certification of the Federal EAS-2348 amplifier and EHE-
1048 gage head.
NOTE: The reversing mechanism on
some EHE series lever-type gage heads does not come with a positive stop (like some other EHE series lever gaging heads do) when rotating from an “over” measurement to an “under measurement. Therefore care should be taken when changing the direction of the gaging head to ensure full scale deflection and appropriate gaging force for optimum repeatability.
Due to its age, and the nature of vintage test equipment it is being sold “AS-IS”. All SALES ARE FINAL. NO RETURNS.
This listing is for the following:
(1)
Federal EAS-2348 electronic amplifier and
(1)
Federal EHE-1048 lever type gage head
The features noted below are taken from Federal Products
sales literature
and may not reflect the actual performance and options of the item for sale and is provided as an overview and for informational purposes only. I will not be held responsible for its accuracy and/or content.
ELECTRONIC AMPLIFIER
FEATURES:
1. Extremely stable magnification, both short and long term.
2. Normal/Reverse polarity switches provided for Gage Head inputs.
3. Long range zero control facilitates set-up.
4. Inch/Metric switch allows measurement in either set of units.
5. Power input module switchable for 117 volt or 220 volt operation.
6. Digital displays have bright, 5/8” high LED numerals for superior visibility.
7. Built-in stand for easier viewing of the meter.
8. Plug-in circuit boards and integrated circuitry for easier serviceability.
Digital
– for applications where:
1.)
Both high resolution and long range are required.
2.) The measurement is a static check – no part motion or exploration is required.
Single vs. Differential Measurement
Single
– for applications where:
1.)
The measured feature is easy to set up on a reference surface.
2.)
Part geometry is controlled or known.
Differential
– for applications where:
1.)
Mechanical references are difficult or impossible.
2.)
Two conditions occur at the same time – size variation and runout, thickness and parallelism, or matching clearances between two parts whose size varies.
SPECIFICATIONS:
Digital Models
Range
Least Digit Value
Inch
Metric
Inch
Metric
±.010”
±200µm
±.010”
.0005”
Range of Zero Adjustment: ±.002”/ ±50µm
Range of Gain Adjustment: 10% of full scale.
Stability – Short Term: less than 0.01% change of gain over an 8 hour period
Stability = Long Term: less than 0.1% change of gain over a 1 month period
Thermal Drift: .01%/°F (0.02%/°C)
Power Requirements: 16 watts (digital), (117V ±10%, 50-60 Hz)
Analog Output: ±10V (full-scale reading) at 5 ma. To a rear mounted connector 75 Ω effective output impedance.
Repeatability: ± 1 digit
Linearity: ± 1 digit
GAGE HEAD
LEVER TYPE
• For use on test stands, surface plate work, or where light pressure is needed.
• Reversing spring allows measurement in either direction.
• Clutch-mounted contact swivels through 200° arc for easy positioning.
• Involute shaped contact automatically corrects for cosine error up to 20°. Alternate contact tips are available**.
• Linearity – 0.1% over full range of ±.010”.
• Gaging pressure less than 4 grams.
• Repeatability better than 4µ”.
• Cable length – 4 feet.
Model EHE-1048 gage head has approximately 2.5 - 4 grams gaging pressure, in either direction (knob on head reverses direction)… positive yet so light you don’t need cumbersome fixtures. Use regular test sets or height stands without the fear of lost motion.
Involute tip automatically corrects for cosine error when finger is at any angle up to 20°. Simplifies “reach over” jobs. Normally furnished. On regular set-ups angle of finger is no longer critical. Ball tip contact is optionally available, easy to substitute.
**
Contact Tips:
EPT-1004 Replacement Tip, .062” steel ball
EPT-1007 Replacement Tip, .031” tungsten carbide ball
EPT-1008 Replacement Tip, steel involute (normally furnished).
EPT-1013 Replacement Tip, .031” steel ball.
The “amplifier and gage head” will only be shipped by USPS priority mail (signature required) within the U.S.A.
I will not ship to post office boxes, unconfirmed addresses or third parties.
I reserve the right to close the auction early in order to permit a local sale.