WAGNER STACK PROBE User manual

DOCUMENT NO:500-72203-001
REV:E
®
WAGNER
ELECTRONICS
WAGNER MODEL L722
"STACK PROBE"
ATTACHMENT
OWNER'S MANUAL

500-72203-001 Rev. EPage 2of 15 L722 Stack Probe Manual
Copyright Notice
Wagner Model L722 “Stack Probe” Attachment Owner’s Manual
© Copyright 2001-2003 Wagner Electronic Products, Inc. All Rights Reserved
Worldwide. No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any other language in
any form by any means without the express written permission of Wagner
Electronic Products, Inc.
Table of Contents
L722 STACK PROBE ATTACHMENT.........................................................................3
L722 SPECIFICATIONS................................................................................................3
L722 CALIBRATION.......................................................................................................3
L722 MAINTENANCE....................................................................................................4
L722 OPERATION..........................................................................................................6
MAINTAINING ACCURACYOF MOISTURE CONTENTREADINGS...................6
REPAIR SERVICE..........................................................................................................9
REPLACEMENT PARTS.............................................................................................10
COIL CORD REPLACEMENT....................................................................................11
WARRANTY..................................................................................................................14
WARNINGS...................................................................................................................15

500-72203-001 Rev. EPage 3of 15 L722 Stack Probe Manual
L722 STACK PROBE ATTACHMENT
The Model L722 Stack Probe attachment, coupled with the L612 Digital
Recording Moisture Meter makes it easy to reach deep into stickered units of
lumber and take accurate moisture readings without the danger of broken pins.
Wagner’s “Wood-Friendly” electromagnetic wave technology makes it possible to
take multiple readings throughout an entire stack in just minutes.
Once the probe is inserted between the boards, the springs press the end-
mounted sensor flat against the wood and ensure deep penetration of the
electro-magnetic field. You then slide the probe slowly out of the stack, reading
the moisture in each board as the sensor passes over it. Virtually unaffected by
surface moisture, the L722 gives consistent and reliable readings in or out of
kilns.
Patents 5,488,312
5,486,815
5,402,076
L722 SPECIFICATIONS
Overall Size Incl. Handle: L722L-L 48in x W 6.0in x H 1.625 in (121.9cm x 15.2cm x 4.12cm)
L722S-L34in x W 6.0in x H 1.625 in (86.3cm x 15.2cm x 4.12cm)
Probe Reach: L722L-L 40.5in (102.8cm)
L722S-L 26.75in (67.9cm)
Extrusion and Sensor Head: 0.5in (12.7mm) thickness
Min/Max Sticker Range: 0.5in –0.9in (12.7mm –22.9mm)
Scanning Area: 2.5in x 2.5in (6.35cm x 6.35cm)
Scanning Depth: 1.0in (2.54cm) minimum
Shipping Weight: L722L-128 oz. (3.64kg)
L722S-112 oz. (3.18kg)
L722 CALIBRATION
Calibration is factory set. Calibrationmay be checked by using the Calibration
Verification Block (included with the L612), and following the instructions in the
L612 Manual. The probe calibration is verified in the same manner as the L612
(Refer to the L612 Owner’s Manual).

500-72203-001 Rev. EPage 4of 15 L722 Stack Probe Manual
L722 MAINTENANCE
CLEANING
Maintenance of the probe consists of cleaning the probe assembly periodically
with mild detergent cleaning solution and a soft rag. Do not soak or submerge
the probe in liquid. Scrape excess pitch off with a flat bladed instrument such as
a chisel or putty knife, being careful not to dig into the probe. Never use solvent
of any kind for cleaning.
SPRING REPLACEMENT
When cleaning under the springs, remove the springs. NEVER lift up on the
springs this will distort the metal. If the springs should become damaged in any
way replace them in pairs. Replacement springs are included in the L722 Parts
Kit (#880-72202-001), which may be purchased from the factory or through your
distributor.
LABEL#735-72200-001REV.A
IMPORTANT!
CLEAN INSTRUMENTDAILY.
NEVER USE SOLVENTOF ANY KIND FOR CLEANING.
MAINTENANCE OFTHE PROBE CONSISTS OFCLEANINGTHEPROBE
ASSEMBLY PERIODICALLY WITH MILD DETERGENTCLEANING
SOLUTIONANDASOFTRAG.
SCRAPE EXCESS PITCHOFFWITH AFLAT BLADED INSTRUMENT
SUCHAS ACHISELORPUTTY KNIFE,BEING CAREFULNOT TO DIG
INTO THE PROBE.
NEVER SOAK OR SUBMERGE
INSTRUMENTINANY LIQUID
Symbol Description
AREMOVE HEX SOCKET CAP SCREWS.
REPLACE SPRINGS.

500-72203-001 Rev. EPage 5of 15 L722 Stack Probe Manual
HINGE REPAIR/REPLACEMENT
If the hinge becomes stretched, removal of the hinge screws and reseating of the
hinge is all that is normally necessary. (Waiting for 30 minutes with the hinge
removed will allow the hinge material to relax). If the hinge is severely distorted,
a replacement can be obtained by purchasing the L722 Parts Kit
(#880-72202-001).
LABEL#735-72200-001REV.A
IMPORTANT!
CLEAN INSTRUMENTDAILY.
NEVER USE SOLVENTOF ANY KIND FOR CLEANING.
MAINTENANCE OFTHE PROBE CONSISTS OFCLEANINGTHEPROBE
ASSEMBLY PERIODICALLY WITH MILD DETERGENTCLEANING
SOLUTIONANDASOFTRAG.
SCRAPE EXCESS PITCHOFFWITH AFLAT BLADED INSTRUMENT
SUCHAS ACHISELORPUTTY KNIFE,BEING CAREFULNOT TO DIG
INTO THE PROBE.
NEVER SOAK OR SUBMERGE
INSTRUMENTINANY LIQUID
Symbol Description
AREMOVE HINGE SCREWS, AND RESEAT OR REPLACE HINGE.
REPLACEMENT SCREWS: INCLUDED IN THE L722 PARTS KIT
(#880-72202-001).
STORAGE
The stack probe should be stored in a cool dry environment.

500-72203-001 Rev. EPage 6of 15 L722 Stack Probe Manual
L722 OPERATION
To connect aprobe to the L612, remove the dust plug from the beige-colored
port labeled “PROBE” on the meter and plug the connecting cable into this port.
With the probe connected tothe L612 and the meter ON, insert the probe into the
sticker space between the layers of boards in a stack of lumber. The springs
press the end-mounted sensor flat against the wood. The actual sensing area of
the probe is located inthe end of the probe assembly on the opposite side of the
springs. Be sure to insert and remove the probe straight in and straight out of the
stack of lumber to avoid damage to the L722 springs and hinge.
When the probe is connected to the meter, the internal hand-meter sensor is
bypassed and the probe will be the source of the readings. The backlight will also
be turned on automatically for easier viewing in the dark kiln environment.
MAINTAINING ACCURACY OF MOISTURE CONTENT READINGS
The purpose of this section is to provide proper moisture content measurement
techniques during kiln drying operations. The major factor of preserving
consistent readings is to control the many variables that are present when
moisture content (MC) values are measured. The control of these variables will
be identified and addressed in the following paragraphs.
Taking L722 Stack Probe Measurements –The probe should be
checked for proper calibration prior to use. This can be accomplished by
verifying the stack probe on the calibration block. The L612 meter should be
checked for general operation and battery condition. Ensure the L612 meter has
been selected for the appropriate wood species being measured. Verify a good
connection with the coil cord at the meter by making sure the moisture content
value doesn’t drift while wiggling the cable.
Consistent use of the stack probe will maintainthe integrity of MC readings.
Ensure the sensor plate area is completely covered by the lumber being
measured. Take several measurements with the probe oriented along the length
of the board, measure close to the “stickers” as wood surfaces will be more
uniform at these locations.
Don’t pull down on the probe handle because hinge damage may occur.
The kiln drying operations procedure should spell out the specific number of
measurements to take, at what depth in the stack to measure, and when to
measure them in the drying cycle. In order to maintain consistency, take readings
in the same locations in the stack, and at the same times in the drying cycle from

500-72203-001 Rev. EPage 7of 15 L722 Stack Probe Manual
one kiln charge to the next. You should take enough readings to be statistically
significant. The more readings you take, the more accurate your “average” will
be.
When taking measurements using a stack probe, you will be measuring the
selected locations in the stack as stated in your kiln drying operations procedure.
This will be the average moisture content of the scan area being measured
directly under the sensor plate.
Keep in mind that the scan area of the L722 stack probe is 2.5” square (6.35cm)
by 1” deep (2.54cm). This varies greatly from an in-line system, which has a
much wider scan area (up to 12” square, 30.5cm), and deeper penetration. This
will cause a larger area to be “averaged” with an in-line system.
The L722 stack probe readings will read excessively high when measuring
severely knotted lumber due to higher density. Readings will be best when
measured on a clear, flat area on the wide face of the lumber that is free of
defects. If there is noticeable surface moisture, try not to measure at that spot
until the moisture dissipates, or skip the area completely. As the moisture
disperses, the effect will be minimized.
Kiln Drying, Moisture Gradients, and Temperature –Warm lumber
tends to lose moisture after it is removed from the kiln and it continues to dry. It
can also absorb moisture from the air in humid conditions during storage prior to
planing. The moisture content of kiln-dried lumber is typically higher in the center
core and dryer towards the ends and outer surfaces. Planing the dryer top and
bottom sections of a board will cause the MC value to be higher. Because it is
difficult to control all of these elements, it is best to try to maintain consistency in
storage, and apply a correction factor as discussed in the paragraph below.
Frozen lumber can affect the MC readings. Wagner Electronics has found that if
frozen lumber has a moisture content value lower than 15%, the readings are
accurate. If the MC is higher than 15%, the actual reading obtained may be
lower than the true value.
In a goodmeasurement process consistency, repeatability, and correlation are
the key factors. The goal is a better FINAL lumber product that meets your
moisture content and grade goals. The closer your final product is to your target
MC, the more cost efficient your drying process will be.
Here are some questions to ask yourself: Are all of your personnel taking the
same number of readings? Are the readings being taken at the same time in the
kiln dry schedule? Has my meter calibration been recently verified? Are the
readings being taken at the same location in the same packs every time? This is
the key to repeatability!

500-72203-001 Rev. EPage 8of 15 L722 Stack Probe Manual
Applying Correction Factors-Due to variances beyond the control of the
user, the MC values obtained from kiln dried lumber as read from the L612/L722
combination will likely not be exactly the same as read by an in-line system. An
effective method to compensate for this is to establish a correction factor based
on the nominal readings obtained in the kiln and the desired (target) MC reading
as seen at the console. You should be looking for a correlation between the
stack probe readings and the in-line readings.
Example: I measured packs 3, 7, 10 and 12of 2x4 Douglas Firin Kiln #1 by
taking 50 readings in each pack after 20 hours of drying. I obtained a hot check
average of 18%. I know the MC of this lumber going through the planer 3 days
from now will have a 16.5% average.
Use the stack probe MC as a reference and adjust your correction factor as
necessary to obtain the desired target MC at the in-line console. Compile data
from previous kiln cycles to fine-tune your correction factor.
Consistency is the key! If your process changes, consider the impact to your
correction factor, but do everything possible to control the variables. Don’t
complicate the variables by measuring one way this time and another way the
next.
If your consistent correction factor suddenly stops working ask yourself: What
has changed? Were the hot check readings taken the same way? Did the
lumber have more MC variability going into the kiln? Did the meter recently get
calibrated? Did the pack coming out of the kiln go through the planer sooner or
later than usual?
Temperature can also have a small effect on the readings. We now know that
high lumber temperatures can cause the MC reading to increase by 2-3%. These
variances are far smaller than would be seen with a resistive pin meter. Some of
this temperature related measurement error could be attributed to the warm
lumber losing moisture as it cools.
Try to measure the lumber at approximately the same temperature from one
cycle to the next to maintain the best consistency in your readings. If possible,
let the wood cool for a couple of hours prior to measurement. Thetemperature
effect is small, and correlation is the real goal, but more accuracy can be
obtained by letting the temperature stabilize.

500-72203-001 Rev. EPage 9of 15 L722 Stack Probe Manual
REPAIR SERVICE
In the event of damage or failure, the probe head can be removed from the
extrusion. Open the handle and release the extrusion cable from the modular
plug (see Figure 1). Remove the two hinge dock screws (see Figure 2). Gently
pull the probe head and its attached cable from the extrusion.
Contact Wagner Electronics to obtain an RMA number & arrange for repair
service:
Wagner Electronic Products, Inc.
326 Pine Grove Road
Rogue River, Oregon 97537
[phone]
Youhave the option of sending in your entireStack Probe or the Stack Probe
Head. Your equipment will be repaired, calibrated, and returned promptly.
If you would like to expedite the probe repair, a replacement probe head can be
ordered and shipped to you directly by Wagner (Part# 860-72201-001 (long) or
860-72201-002 (short)).
Coupler
Depress lever and extract
plug from coupler
Figure 1

500-72203-001 Rev. EPage 10 of 15 L722 Stack Probe Manual
HINGE DOCKSCREWS
IMPORTANT!
CLEAN INSTRUMENTDAILY.
NEVER USE SOLVENTOF ANY KIND FOR CLEANING.
MAINTENANCE OFTHE PROBE CONSISTS OFCLEANINGTHEPROBE
ASSEMBLY PERIODICALLY WITH MILD DETERGENTCLEANING
SOLUTIONANDASOFTRAG.
SCRAPE EXCESS PITCHOFFWITH AFLAT BLADED INSTRUMENT
SUCHAS ACHISELORPUTTY KNIFE,BEING CAREFULNOT TO DIG
INTO THE PROBE.
NEVER SOAK OR SUBMERGE
INSTRUMENTINANY LIQUID
LABEL#735-72200-001REV.A
Figure 2
REPLACEMENT PARTS
Several parts can be ordered for the L722 using the part numbers as follows:
L712/L722 External Coil Cord #830-71201-001
Probe Head, Long #860-72202-001
Probe Head, Short #860-72202-002
L722 Parts Kit #880-72202-001
(L722 Parts Kit Includes: 4 Springs, 1 hinge, 2 probeend screws, 5 hinge
screws & 2 Hex L-Keys).