User guide

OPERATION Protocol Plus Owner’s Manual
40 Version 2
Copyright © 2010 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
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5.6.10.5. Adjusting Actual Versus Displayed Parameters
Two points of display calibration (temperature offset) are available. The Zone 1 Actual
and Zone 2 Actual parameters are the two temperature points where the offset is to take
effect. These values are adjustable. The Zone 1 and Zone 2 Displayed parameters are the
values the user wishes to have displayed at the Actual temperatures, and are also
adjustable.
For example, the control is displaying 400°F with the setpoint being 400°F, but the center
of the oven chamber is actually 395°F. This can occur due to oven wall losses and
product loading variations. The operator may change the zone calibration so that the
center of the oven is 400°F when the display reads 400°F. In this case operate the oven in
manual mode with a setpoint of 400°F. Record the center of the chamber (as measured
with an independent sensor). Access the Zone Calibration Page and enter this measured
value as the Zone 2 Actual value, with 400° as the Zone 2 Displayed value.
Zone 1 can be adjusted using the same method at a lower temperature. The instrument
will then create a linear offset based on the Zone1 and Zone 2 Actual temperature values.
Note that the oven does not have to be heated to adjust the zone parameters if the zone
values are known based on prior experience.
5.6.10.6. Setting up the Sensor Calibration Page
The Sensor Calibration Page has parameters which can change the internal calibration of
the temperature sensor input signal. There is a low and high calibration point for both the
control sensor and the high limit sensor. To calibrate the instrument, allow the control to
warm up for at least 30 minutes.
5.6.10.7. Access Sensor Calibration Page
1. Enter Setup Mode.
2. Press Page until Sensor Cal displays.
3. Press Menu.
4. Change each parameter by pressing Menu until the desired parameter is displayed,
and then press ▲ or ▼ to change the value.
The control may have the optional process value retransmission output feature. The
output is a 1 to 5VDC signal. To calibrate the retransmit signal, the RetOutLo and
RetOutHi values from the Control Page must be known. Bypass calibrating the control
and high limit sensor input and access the retransmit calibration by pressing the Menu
until RetCalLo displays (skip steps 4-17). Table 12 shows the menu items available.
To re-calibrate the instrument:
1. Disconnect the control and high limit sensor thermocouples.