Hanna Instruments HI 83099 User Manual

Page 23

• Reinsert the cuvette into the instrument.

• Press

Timer and the display will show the countdown prior to the measurement or, alternatively, wait

for 6 minutes and press

Read. When the timer ends the meter will perform the reading. The instrument

displays concentration in

µµµµµ

g/L of chromium VI.

• Press ▲ or ▼ to access the second level functions.
• Press the

Chem Frm key to convert the result in

g/L of Chromate (CrO

¯) and Dichromate (Cr

¯).

• Press ▲ or ▼ to return to the measurement screen.

INTERFERENCES

Interference may be caused by:
Vanadium above 1 ppm. However, waiting 10 minutes before reading, the interference is removed.
Iron above 1 ppm
Mercurous and mercuric ions cause slight inhibition of the reaction.

Chromium VI LR

CHROMIUM VI LOW RANGE

SPECIFICATIONS

Range

0 to 300

g/L

Resolution

g/L

Accuracy

±1

g/L ±4% of reading at 25 °C

Typical EMC

±1

g/L

Deviation
Light Source

Tungsten lamp with narrow band interference filter @ 525 nm

Method

Adaptation of the

ASTM Manual of Water and Environmental Technology, D1687-92,

Diphenylcarbohydrazide method. The reaction between chromium VI and the reagent
causes a purple tint in the sample.

REQUIRED REAGENTS

Code

Description

Quantity

HI 93749-0

Powder reagent

1 packet

REAGENT SETS

HI 93749-01 Reagents for 100 tests
HI 93749-03 Reagents for 300 tests
For other accessories see page 132.

MEASUREMENT PROCEDURE

• Select the

Chromium VI LR method using the procedure described in

the

Method Selection section (see page 12).

• Fill the cuvette with 10 mL of unreacted sample (up to the mark)

and replace the cap.

• Place the cuvette into the holder and close the lid.

• Press the

Zero key. The meter will show “-0.0-” when the meter is zeroed and ready for

measurement.

• Remove the cuvette and add the content of one packet of

HI 93749-0 reagent. Replace the cap and shake vigorously
for about 10 seconds.

10 mL