Watlow Controls 981 Series Use and care manual

Calibrating Watlow
Process Controls
(Applies to Series 981, 982, 983, 984, 986, 987, 988, 989)
Calibration Manual
Watlow Controls, 1241 Bundy Blvd., P.O. Box 5580, Winona, MN 55987-5580, Phone: [phone], Fax: [phone]
W988-CM10-9345
November, 1993 $5.00
Made in the U.S.A.
Printed on Recycled Paper

2WATLOW Series 988 Calibration Manual
Contents
Page Description
Calibrating Your Watlow Process Control
3 The Factory (Fcty) Menus
3 Entering the Fcty Prompt
4 Diagnostics Menu
6 Calibration Menu
7 Calibration Restore Prompt
7 The dFL Prompt
7 Input Calibration
7 Output Calibration
Calibration Procedures
8 Low Gain Thermocouple Input
9 High Gain Thermocouple Input
10 RTD Input
11 mA Process Input
12 VDC Process Input
13 mVDC Process Input
14 Slidewire Feedback Input
14 Current Transformer Input
15 mA Process Output 1 and 2
16 VDC Process Output 1 and 2
17 mA Retransmit Output 3
17 VDC Retransmit Output 3

WATLOW Series 988 Calibration Manual 3
Menus/Prompts
Calibrating Your Watlow Process Control
This manual is a supplement to the Series 981/982 and 988/989 User’s Manual.
The calibration procedures within this manual pertain to the following controls:
Series 981 Series 986
Series 982 Series 987
Series 983 Series 988
Series 984 Series 989
Use in conjunction with the appropriate user’s manual. From this point on, 988 will
be used in place of the above listed models.
Before attempting to calibrate, make sure you read through the
procedures carefully and have the proper equipment called for
in each procedure.
The Factory (Fcty) Menus
The Fcty prompt consists of three menus: PLOC, diAg, and CAL. The Fcty prompt
will not appear if the hardware lockout DIP switch is ON. Refer to Chapter 1 of the
User’s Manual (white book).
• The Panel Lockout (PLOC) menu is explained in detail in the Series 988
User’s Manual.
• The Diagnostics (diAg) menu contains specific information for each control. It
is explained in detail on Page 4 of this manual.
• In the Calibration menu (CAL), various input signals must be supplied for the
control to go through its auto calibration. See Page 5 for the complete
Calibration menu and procedures.
Make sure the input type DIP switches are in the proper position before beginning.
Refer to the 988 User’s Manual.
Entering the Fcty Prompt
The Fcty prompt can only be entered from the SEt prompt.
• Press the Up/Down keys simultaneously for 3 seconds ( ±1 second). Any inad-
vertent change in the displayed data, when pressing the Up/Down keys is
ignored. The SEt prompt appears in the lower display.
• Continue pressing the Up/Down keys simultaneously for another 3 seconds and
the Fcty prompt appears in the lower display with PLOC in the upper display.
For 981 - 984 units the dIAg prompt appears in the upper display.
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
Figure 1 -
Entering the
Fcty Prompt
3 Seconds
NOTE:
The Fcty menu is
not available on a
Series 981 - 984.
NOTE:
The Series 981 - 984
units have a
Hold/Run key in
place of the
Auto/Man key.

TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
4WATLOW Series 988 Calibration Manual
Diagnostics
Diagnostics Menu
The Diagnostics menu (diAg) contains specific information for each control. This
menu is for factory use only, but can be accessed for viewing or technical assis-
tance.
• At the Fcty prompt, press the Up or Down key to advance the upper display to
the diAg prompt. See below. Use the Mode key to advance through this menu.
Do not enter any readings here; make photocopies instead.
(diAg)
Software revision
Serial number
Ambient temperature
Ambient A/D count
(Diagnostics)
Factory ship date
Your
Readings
DAtE
SOFt
Sn _
_
AMb
Acnt
gnd
cnt2
itY1
itY2
cnt1
OtY1
OtY2
OtY4
dISP
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
Input 2 A/D count
Input 1 A/D count
Input 1 modul
e
Input 2 module
Ground A/D count
Output 1 module
Output 2 module
Output 4 module
Test displays
Your
Readings
tout ( ) Test outputs
OtY3
( )
( )
Output 3 module
OPLP ( ) Open Loop
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
Figure 2 -
Entering the
Diagnostics Menu
Figure 3 -
The Diagnostics
Menu
Press the Mode key to advance
through the Diagnostics menu.

WATLOW Series 988 Calibration Manual 5
Diagnostics
When contacting the factory for technical assistance, make sure you have the informa-
tion documented from the following prompts. All prompts in this menu are read only.
Date: This prompt represents the date the final control test was performed. The first
two numbers are the week (01 through 52), and the last two numbers are the year.
Software Revision: Signifies the control software revision.
Serial Number: Represents the control serial number. The first two LED’s in the
upper display are Sn followed by the serial number. The number is six digits in
length beginning with the last two digits in the upper display, and wrapping around
to the lower display where the remaining four digits are shown.
Ambient Temperature: The ambient temperature at the Input 1 terminals, in °F.
Acnt, gnd, cnt1 and cnt2 are for factory use only.
itY1, itY2, OtY1, OtY2, OtY3, and OtY4 are input and output module types respec-
tively. Below is a listing of the displays, and what they represent. Please docu-
ment the displays before contacting the factory for technical assistance.
Input Types
nonE No module Utch Universal thermocouple high gain
tc Thermocouple only UtcL Universal thermocouple low gain
Curr Current detect UMu Universal millivolts
SLid Slidewire UPrc Universal process
UOFF Universal OFF Ei2 Event input 2
Urtd Universal RTD Curr Heater current
Output Types
nonE No module rLAB Relay A/B
SSR1 0.5A SSR rABS Relay A/B with suppression
SS1S 0.5A SSR with suppression 2rLY Two relays
SSr2 2.0A SSR Proc Process
SS2S 2.0A SSR with suppression Uret Voltage/retransmit
2SSr Two 0.5A SSR Iret Current/retransmit
dc Switched DC SPLY Power supply
2dc Two switched DC 232 RS-232 communications
rLYc Form C relay 485 EIA-485/422 communications
rLcS Form C relay with suppression
Display: Press the Up or Down key to change the upper display from no to YES. Each
display and LED is tested. If any display or LED is absent contact the factory.
Test Output: This prompt tests each output. As the Up or Down key is pressed, it
cycles through the available outputs. Once the corresponding LED is lit the respective
output is energized. Press the Up or Down key again to advance to the next output.
If any LED’s are non-functional, or if the outputs fail to energize, contact the factory.
Open Loop: This prompt enables open heater or shorted sensor detect, and
enables the error code function. This prompt only functions in the proportional
control mode. The error message OPLP flashes in the lower display when on is
selected and heat or cool is full ON and no temperature change has occurred over
a period of time. The time period is based on the system characteristics.
Range: on or OFF
Default: OFF
This menu will continue looping through the parameters until you press the
Display key to return to the Display loop.
DAtE
SOFt
Sn
AMb
itY1
itY2
OtY1
OtY2
OtY3
OtY4
dISP
tout
OPLP

6WATLOW Series 988 Calibration Manual
CAL Menu
Calibration Menu
Enter the Factory menu again by pressing the Up and Down keys simultaneously
for three seconds to enter the Setup menu, and an additional three seconds to
enter the Factory menu.
• At the Fcty prompt, press the Up or Down key to advance to the upper display to
the CAL prompt.
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
Figure 5 -
The Calibration
Menu
Figure 4 -
Entering the
Calibration Menu
TL
W
W
A
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 988
MODE
AUTO
MAN
(CAL)
(Calibration)
A 50
tc
A 0H
A 20
A 15
A 00
A380
A 0U
A20A
b 15
b380
A10U
b10U
b 0U
b 4
A
b 0
u
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
Your Settings
b100
1 4
1 20
1 0
1 10
2 4
A 4A
b20A
Default parameters
Your Settings
2 20
2 0
2 10
3 LO
3 HI
rSt
dFL
A 0u
A100
b 00
b 0H
b 50
( )
( )
( )
( )
( )
( )b 20
Restore factory values
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
( )
Input #1
Input #2
Input #2
(cont.)
Output #1
Output #2
Output #3
The Calibration menu begins with the Input 1 prompts and continues through to the
Output 3 prompts. Located at the end of the Calibration menu are the “restore fac-
tory values” and “default parameters” prompts. See below.
Before continuing through the calibration menu, refer to the proper calibra-
tion procedure for your control.
Press the Mode key to advance
through the Diagnostics menu.

WATLOW Series 988 Calibration Manual 7
rSt/dFL Prompts
Calibration Restore Prompt
If you make a mistake while calibrating your control, the rSt prompt near the end of
the calibration menu restores the original factory calibration settings. At the rSt
prompt, simply press the Up or Down key to change the upper display to read YES;
press the Mode key. The original factory calibration values are restored.
The dFL Prompt
To set the operating parameter defaults for either domestic or international, use
the dFL (default) prompt at the end of the Calibration menu. Once you have
entered the Calibration menu, use the Mode key to advance to the dFL prompt.
Press the Up or Down key to change the upper display to US or SI. For domestic
prompts, select US and receive:
•°F • Rate in minutes
• Proportional band in degrees or units • Reset in repeats per minute
For international prompts, select SI and receive:
•°C • Derivative in minutes
• Proportional band in % of span • Integral in minutes per repeat
Input Calibration
Once you enter the Factory menu, press the Up or Down key until the CAL prompt
appears in the upper display with Fcty in the lower display. Press the Mode key to
advance to the first calibration prompt. See Figure 2 on the previous page. The
upper display shows the prompt default no, while the lower display indicates the
input signal prompt.
Each input calibration prompt is preceded by an A or B, signifying Input 1 or 2
respectively. Refer to the Calibration menu on the previous page again. Before
advancing to the next prompt when calibrating, always apply the correct input signal
and allow to stabilize for 10 seconds before changing the upper display to YES. If
the parameter is left at no, the calibration information will not be entered. Once the
appropriate parameters are calibrated, press the Display key to exit the CAL menu.
Output Calibration
After calibrating the Input 1 and 2 prompts, the next prompts apply to Output 1
through 3 which are for process outputs only.
Model numbers affected are Output 1 98_ _ - _ _ F_ - _ _ _ _
Output 2 98_ _ - _ _ _ F- _ _ _ _
Output 3 98_ _ - _ _ _ _ - M_ _ _
98_ _ - _ _ _ _ - N_ _ _
The prompt in the lower display indicates the output signal while the upper display
reads a hexidecimal value which matches the output value. The upper display
value is for internal use only and should be ignored.
Each output calibration prompt is preceded by a 1, 2, or 3, signifying Output 1, 2, or 3
respectively. If your unit does not have Output 2 or 3, these prompts will not appear.
Once the appropriate parameters are calibrated, press the Display key to exit the
CAL menu.

Low Gain Thermocouple Input Procedure
For all thermocouple inputs excluding Type R, S and B
Equipment Required
• Type J reference compensator with reference junction at 32°F/0°C, or
Type J thermocouple calibrator set at 32°F/0°C
• Precision millivolt source, 0 - 50mV minimum range, 0.01mV resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the Series
988. See Chapter 2 in the user's manual.
2. For Input #1 calibration: Connect the millivolt source to terminal #9 (+) and
terminal #10 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire. If
you have model number 98_ _ - 2_ _ _ - _ _ _ _, remove the control from the
case and set the Input 1 DIP switches to: 1 OFF 2 ON 3 ON
For Input #2 calibration: Connect the millivolt source to terminal #19 (+) and
terminal #20 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire. If
you have model number 98_ _ - _2_ _ - _ _ _ _, remove the control from the
case and set the Input 2 DIP switches to: 1 OFF 2 ON 3 ON
3. Apply power to the unit and let it warm up for 15 minutes. After warm-up, put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A 50 prompt, or the B 50 prompt, enter 50.00mV from the millivolt source
to the Series 988. Allow at least 10 seconds to stabilize. Press the Up key to
change the upper display to YES. Press the Mode key.
5. At the A 00 prompt, or the B 00 prompt, enter 0.00mV from the millivolt source
to the Series 988. Allow at least 10 seconds to stabilize. Press the Up key to
change the upper display to YES. Press the Mode key.
6. At the tc prompt, disconnect the millivolt source, and connect the reference
compensator or T/C calibrator to terminal #9 (+) and terminal #10 (-) on the 988
terminal strip. If using a compensator, turn it on and short the input wires.
When using a Type J calibrator, set it to simulate 32°F/0°C. Allow 10 seconds
for the control to stabilize. Press the Up key to change the upper display to
YES. To conclude the T/C calibration, press the Display key.
8WATLOW Series 988 Calibration Manual
Low Gain T/C
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2.

WATLOW Series 988 Calibration Manual 9
High Gain T/C
High Gain Thermocouple Input Procedure
Type R, S and B only
Equipment Required
• Type J reference compensator with reference junction at 32°F/0°C, or
Type J thermocouple calibrator set at 32°F/0°C
• Precision millivolt source, 0 - 50mV minimum range, 0.01mV resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Input #1 calibration: Connect the millivolt source to terminal #9 (+) and
terminal #10 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire. If
you have model number 98_ _ - 2_ _ _ - _ _ _ _, remove the control from the
case and set the Input 1 DIP switches to: 1 OFF 2 ON 3 ON
For Input #2 calibration: Connect the millivolt source to terminal #19 (+) and
terminal #20 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire. If
you have model number 98_ _ - _2_ _ - _ _ _ _, remove the control from the
case and set the Input 2 DIP switches to: 1 OFF 2 ON 3 ON
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A 50 or B 50 prompt, enter 50.00mV from the millivolt source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key.
5. At the A 00 or B 00 prompt, enter 0.00mV from the millivolt source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key.
6. At the tc prompt, disconnect the millivolt source, and connect the reference
compensator or T/C calibrator to terminal #9 (+) and terminal #10 (-) on the 988
terminal strip. If using a compensator, turn on and short the input wires. If
using a J calibrator, set it to simulate 32°F/0°C. Allow 10 seconds for the con-
trol to stabilize. Press the Up key to change the upper display to YES. To con-
clude the T/C calibration, press the Display key.
7. For Input #1 calibration: Remove the control from the case and set the
Input #1 DIP switches to: 1 OFF 2 ON 3 OFF
8. For Input #2 calibration: Remove the control from the case and set the Input
#2 DIP switches to: 1 OFF 2 ON 3 OFF
9. At the A 0H or B 0H prompt, enter 0.00 mV from the millivolt source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key.
10.At the A 20 or B 20 prompt, enter 20.00 mV from the millivolt source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press and hold the Mode key, while also pressing
the Up key until the lower display reads tc.
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2.

10 WATLOW Series 988 Calibration Manual
RTD
RTD Input Procedure
Equipment Required
•1Kprecision decade box with 0.01resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Input #1 calibration: Connect the decade box to terminals #8, 9
and 10 on the 988 terminal strip, see below. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 1 DIP switches to:
1 OFF 2 OFF 3 ON
For Input #2 calibration: Connect the decade box to terminal #18, 19 and 20
on the 988 terminal strip, see below. Use 20 to 24 gauge copper wire. If you
have model number 98_ _ - _2_ _ - _ _ _ _, remove the control from the case
and set the Input 2 DIP switches to: 1 OFF 2 OFF 3 ON
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2. 3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A 15 or B 15 prompt, enter 15.00from the decade box to the Series
988. Allow at least 10 seconds to stabilize. Press the Up key to change the
upper display to YES. Press the Mode key.
5. At the A380 or B380 prompt, enter 380.00from the decade box to the Series
988. Allow at least 10 seconds to stabilize. Press the Up key to change the
upper display to YES. Press the Mode key. To conclude the RTD calibration,
press the Display key.
H
L
G
Ω
General Radio Model #1433-T
To 8 or 18
To 9 or 19
To 10 or 20
Series 98X
Terminals

WATLOW Series 988 Calibration Manual 11
mA Process Input
mA Process Input Procedure
0 to 20mA and 4 to 20mA units
Equipment Required
• Precision current source, 0-20mA range with 0.01mA resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Input #1 calibration: Connect the voltage source to terminal #8 (-) and
terminal #10 (+) on the 988 terminal strip. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 1 DIP switches to:
1 ON 2 ON 3 ON
For Input #2 calibration: Connect the voltage source to terminal #18 (-) and
terminal #20 (+) on the 988 terminal strip. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 2 DIP switches to:
1 ON 2 ON 3 ON
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A20A or B20A prompt, enter 20.00mA from the current source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key.
5. At the A4Aor B 4A prompt, enter 4.00mA from the current source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key. To conclude the current
process calibration, press the Display key.
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2.

12 WATLOW Series 988 Calibration Manual
VDC Process Input Procedure
0 to 5VDC and 0 to 10VDC units
Equipment Required
• Precision Voltage source 0-10 volt minimum range with .001 volt resolution.
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See chapter 2 in the user’s manual.
2. For Input #1 calibration: Connect the voltage source to terminal #9 (+)
terminal #10 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 1 DIP switches to:
1 ON 2 ON 3 ON
For Input #2 calibration: Connect the voltage source to terminal #19 (+) and
#20 (-) on the 988 terminal strip. Use 20 to 24 gauge copper wire. Remove the
control from the case and set the Input 2 DIP switches to:
1 ON 2 ON 3 ON
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A10U or B10U prompt, enter 10.000 volts from the voltage source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key .
5. At the A 0U or B 0U prompt, enter 0.000 volts from the voltage source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key . To conclude the voltage
process calibration press the Display key.
VDC Process Input
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2.

WATLOW Series 988 Calibration Manual 13
mVDC Process Input
mVDC Process Input Procedure
0 to 50mVDC and 0 to 100mVDC units
Equipment Required
• Precision millivolt source, 0-100mV minimum range with 0.001mV resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Input #1 calibration: Connect the millivolt source to terminal #8 (-) and
terminal #10 (+) on the 988 terminal strip. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 1 DIP switches to:
1ON 2OFF 3ON
For Input #2 calibration: Connect the millivolt source to terminal #18 (-) and
terminal #20 (+) on the 988 terminal strip. Use 20 to 24 gauge copper wire.
Remove the control from the case and set the Input 2 DIP switches to: 1 1
ON 2 OFF 3 ON
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Input 1 prompts
(beginning with an “A”) first, then continue on to the Input 2 prompts
(beginning with a “B”). See the Calibration menu on Page 6.
4. At the A 0U or B 0U prompt, enter 0.000mV from the millivolt source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key.
5. At the A100 or B100 prompt, enter 100.00mV from the voltage source to the
Series 988. Allow at least 10 seconds to stabilize. Press the Up key to change
the upper display to YES. Press the Mode key. To conclude the millivolt
process calibration, press the Display key.
NOTE:
Any prompt begin-
ning with an “A”
applies to Input 1.
Those beginning
with a “B” apply to
Input 2.

14 WATLOW Series 988 Calibration Manual
Slidewire/Current
Slidewire Feedback Input Procedure
Equipment Required
•1Kprecision decade box with 0.01resolution
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. Connect the decade box to terminal #18 and #20 on the 988 terminal strip.
Place a jumper wire between terminal #19 and #20. Use 20 to 24 gauge cop-
per wire.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
4. At the B 15 prompt, enter 1000.00from the decade box to the Series 988.
Allow at least 10 seconds to stabilize. Press the Up key to change the upper
display to YES. Press the Mode key.
5. At the B380 prompt, remove the jumper from terminals #19 and #20 and place
it between terminals #18 and #19. Allow at least 10 seconds to stabilize.
Press the Up key to change the upper display to YES. Press the Mode key.
To conclude the slidewire feedback calibration, press the Display key.
Current Transformer Input Procedure
Equipment Required
• DC source, 50mA minimum sourcing capacity, 0 - 5V minimum range
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. Connect the voltage source to terminal #18 and terminal #20 on the 988 termi-
nal strip. Use 20 to 24 gauge copper wire.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
4. At the B 50 prompt, enter 4.72VDC from the voltage source to the Series 988.
Allow at least 10 seconds to stabilize. Press the Up key to change the upper
display to YES. Press the Mode key.
5. At the B 00 prompt, enter 0.00VDC from the voltage source to the Series 988.
Allow at least 10 seconds to stabilize. Press the Up key to change the upper
display to YES. Press the Mode key. To conclude the current transformer
input calibration, press the Display key.

WATLOW Series 988 Calibration Manual 15
mA Process Output
mA Process Output 1 & 2 Procedure
Equipment Required
• 4 1/2 digit digital multimeter
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Output #1 calibration: Connect the digital multimeter to terminal
#12 (+) and terminal #14 (-). Set the DMM to read a range of 0 to 20mA.
Connect the leads of the DMM to measure current.
For Output #2 calibration: Connect the digital multimeter to terminal
#15 (+) and terminal #17 (-). Set the DMM to read a range of 0 to 20mA.
Connect the leads of the DMM to measure current.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Output 1 prompts
(beginning with a “1”) first, then continue on to the Output 2 prompts
(beginning with a “2”). See the Calibration menu on Page 6.
4. At the 1 4 or 2 4 prompt, the multimeter should read approximately 4 mA. Use
the Up or Down keys to adjust the reading on the multimeter for 3.85mA
±.05mA. Allow the control to stabilize for 10 seconds. Press the Mode key to
enter and advance to the next prompt.
5. At the 1 20 or 2 20 prompt, use the Up or Down keys to adjust the reading on
the multimeter for 20.15mA ±.05mA. Allow the control to stabilize for 10 sec-
onds. Press the Mode key to enter and advance to the next prompt. To con-
clude the process output calibration, press the Display key.
NOTE:
Any prompt begin-
ning with a “1”
applies to Output 1.
Those beginning
with a “2” apply to
Output 2.

16 WATLOW Series 988 Calibration Manual
VDC Process Output
VDC Process Output 1 & 2 Calibration
Equipment Required
• 4 1/2 digit Digital Multimeter
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user's manual.
2. For Output #1 calibration: Connect the digital voltmeter to terminal #13 (+)
and terminal #14 (-). Set the DVM to read a range of 0 to 10VDC. Connect the
leads of the DVM to measure volts DC.
For Output #2 calibration: Connect the digital multimeter to terminal
#16 (+) and terminal #17 (-). Set the DVM to read a range of 0 to 10VDC.
Connect the leads of the DVM to measure volts DC.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
When performing calibration procedures, always do the Output 1 prompts
(beginning with a “1”) first, then continue on to the Output 2 prompts
(beginning with a “2”). See the Calibration menu on Page 6.
4. At the 1 0 or 2 0 prompt, the multimeter should read approximately 0 Volts.
Use the Up or Down keys to adjust the reading on the multimeter for 0.0VDC ±
0.1VDC. Allow the control to stabilize for 10 seconds. Press the Mode key to
enter, and advance to the next prompt.
5. At the 1 10 or 2 10 prompt, use the Up or Down keys to adjust the reading on
the multimeter for 10.0VDC ±0.1VDC. Allow the control to stabilize for 10 sec-
onds. Press the Mode key to enter, and advance to the next prompt. To con-
clude the process output calibration, press the Display key.
NOTE:
Any prompt begin-
ning with a “1”
applies to Output 1.
Those beginning
with a “2” apply to
Output 2.

WATLOW Series 988 Calibration Manual 17
Retransmit
mA Retransmit Output 3 Procedure
Equipment Required
• 4 1/2 digit Digital Multimeter
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the user’s manual.
2. Connect the digital multimeter to terminal #1 (+) and terminal #2 (-). Set the
DVM to read a range of 0 to 20mA. Connect the leads of the DVM to measure
current.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
4. At the 3 LO prompt, the multimeter should read approximately 0.1mA. Use the
Up or Down keys to adjust the reading on the multimeter for 0.00mA ±0.05mA.
Allow the control to stabilize for 10 seconds. Press the Mode key to enter and
advance to the next prompt.
5. At the 3 HI prompt, use the Up or Down keys to adjust the reading on the multi-
meter for 20mA ±.05mA. Allow the control to stabilize for 10 seconds. Press
the Mode key to enter and advance to the next prompt. To conclude the
process retransmit output calibration, press the Display key.
VDC Retransmit Output 3 Calibration
Equipment Required
• 4 1/2 digit Digital Multimeter
Setup and Calibration
1. Connect the AC voltage L1, L2 and ground to the proper terminals on the
Series 988. See Chapter 2 in the 988 User’s Manual.
2. For Output #1 calibration: Connect the digital multimeter to terminal
#1 (+) and terminal #2 (-). Set the DVM to read a range of 0 to 10VDC.
Connect the leads of the DVM to measure volts DC.
3. Apply power to the unit and let it warm up for 15 minutes. After warm up put
the unit in the CAL menu. See Page 6.
4. At the 3 LO prompt, the multimeter should read approximately 0 volts. Use the
Up or Down keys to adjust the reading on the multimeter for 0.0VDC ±0.1 volt.
Allow the control to stabilize for 10 seconds. Press the Mode key to enter, and
advance to the next prompt.
5. At the 3 HI prompt, use the Up or Down keys to adjust the reading on the multi-
meter for 10.0VDC ±0.1VDC. Allow the control to stabilize for 10 seconds.
Press the Mode key to enter, and advance to the next prompt. To conclude the
voltage process retransmit output calibration, press the Display key.

18 WATLOW Series 988 Calibration Manual

Watlow Process Controls Calibration Manual
Watlow Controls, 1241 Bundy Blvd., P.O. Box 5580, Winona, MN 55987-5580, Phone: [phone], Fax: [phone]