In-Situ TROLL 9500 Operators Manual - Manual (Page 75)

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TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
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calculation of slope and offset for 2 ranges (pH 4-7 and pH 7-10).
The correct slope for the pH values being monitored will automati-
cally be applied. A 3-point calibration is useful when the pH range
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Nominal vs. Stable
To shorten the calibration time, you have the option to accept the
calibration when “Nominal” stability conditions are achieved. If the
early value is accepted, the calibration point will be designated “USER
SET” in the calibration report. If the calibration report indicates that
calibration was performed through to stability then the instrument will
operate as intended by In-Situ’s quality standards.
CALIBRATION SOLUTIONS
Calibration solutions certified to N.I.S.T. standards are supplied in the
In-Situ pH Calibration Kit: pH 4, pH 7, pH 10 buffer, and deionized
water. Catalog No. 0032080. Solutions are also available separately.
TIP: Most solutions are usable beyond their stated expiration
date, depending on storage conditions; however, the results
cannot be guaranteed.
Primary standard buffer salts are available from the National Bureau
of Standards, and may be used in situations where extreme accuracy
is required. Commercially available pH buffers may be used.
RECOMMENDED CALIBRATION FREQUENCY
Calibration frequency will depend on the nature of the sample and the
degree of accuracy required. In clean water samples, the pH sensor
should retain its accuracy for 2-6 weeks before requiring recalibration.
Recalibrate the sensor—
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pH QUICK CAL
The procedure to Quick Cal the pH sensor (a 1-point calibration at pH
7), along with other sensors in the Basic Sensor Set, may be found in
Section 3, Getting Started.
To perform a more accurate traditional calibration, follow the proce-
dure below.
TIP: The pH calibration procedure is the same for pH
sensors and pH/ORP sensors.
TRADITIONAL pH CALIBRATION PROCEDURE
1. With a pH or pH/ORP sensor installed and plugs or sensors in the
other ports, rinse the front end of the MP TROLL 9500 in tap water,
then again in deionized water. Shake to dry.
For the most accurate results, follow this with a rinse in a portion of
the selected calibration solution.
2. Insure the black PVC base is attached to the Cal Cup, and fill the
Cal Cup to the fill line with the selected calibration
solution.
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ing a multi-point calibration.
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the lower line as a guide.
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upper line.
3. Insert the front end of the MP TROLL 9500 into the
open end of the Cal Cup. Thread the Cal Cup onto
the body until seated against the o-ring, then back
off slightly to avoid overtightening.
4. Connect the MP TROLL 9500 to a PC and establish
a connection in Win-Situ 4 or Pocket-Situ 4. Win-Situ screens are
illustrated here. The Pocket-Situ interface is similar, with the Navi-
gation tree at the top of the screen and the Information pane below
it.
SECTION 11: PH
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RECOMMENDED CALIBRATION ORDER FOR PH AND ORP
The pH/ORP sensor requires separate calibrations for pH and ORP.
A suggested calibration scenario is as follows:
A. First, Quick-Cal ORP (plus, optionally, other installed Basic sen-
sors). For the procedure, see Section 3, Getting Started.
B. Then, perform a 2- or 3-point Traditional pH calibration as
described here.