Testo pH 4.01 Buffer Solution 250 ml – pH Meter Calibration Fluid, Dosing Bottle, Compatible with Testo 205 and 206 (0554 2061)

Testo pH 4.01 buffer solution (product code 0554 2061) is a reference solution used for the calibration and adjustment of pH meters, supplied in a practical 250 ml dosing bottle. It is used for the pH 4 calibration point on the Testo 205, Testo 206 pH1, Testo 206 pH2 and Testo 206 pH3 pH/temperature meters. According to the bottle label, the solution is traceable to N.I.S.T. and PTB, and the pH value of lot samples is verified by DKD; Testo user manuals list it as DAkkS calibration certified.

pH 4 Point in pH Meter Calibration

On the Testo 205, 1-point calibration is carried out at pH 4, 7 or 10, and 2-point calibration at pH 4–7 or pH 7–10; on the Testo 206 series, 1-, 2- or 3-point calibration can be selected. For a pH 4–7 two-point calibration, this solution is used together with the pH 7.00 buffer solution (Testo 0554 2063). In calibration mode the probe tip is immersed in the buffer solution; when the instrument finds a stable value (less than 0.02 pH change in 20 seconds) it saves the calibration point and finally displays the slope (mV/pH) and offset (mV) values.

Technical Specifications (Official Testo Data)

• Brand / Product: Testo pH 4.01 buffer solution · product code 0554 2061
• pH Value: 4.01 (+25 °C)
• pH by Temperature (bottle label): 5 °C: 4.01 · 10 … 20 °C: 4.00 · 25 … 30 °C: 4.01 · 35 °C: 4.02 · 40 °C: 4.03 · 45 °C: 4.04 · 50 °C: 4.06
• Packaging: 250 ml dosing bottle
• Traceability: traceable to N.I.S.T. and PTB · DAkkS calibration certified (Testo accessory list)
• Storage Temperature: +5 … +35 °C (bottle label)
• Compatible Instruments: Testo 205 · Testo 206 pH1 · Testo 206 pH2 · Testo 206 pH3

Scope of Delivery

• 1 × pH 4.01 buffer solution in a 250 ml dosing bottle

Technician Tips

• Do not let the glass tip touch the bottle: during calibration, the glass part of the pH probe tip must not touch the plastic of the bottle and the instrument must not be left inside the bottle; otherwise a calibration deviation of up to ±0.4 pH may occur.
• Read the label: Testo requires that the usage instructions on the buffer solution label be followed during calibration; the expiry date and lot information are on the bottle label.
• Know the temperature effect: according to the table on the label, the solution's pH value is 4.00 at 10 … 20 °C, 4.03 at 40 °C and 4.06 at 50 °C; check the value for the temperature at which you calibrate in the table.
• Renew the solution on an error code: if Er1 (invalid slope) or Er2 (invalid offset) appears after calibration, repeat the calibration; use fresh buffer solution if necessary.
• Monitor the electrode's service life: if at the end of calibration the slope is below 50 mV/pH or the offset is above 60 mV, the pH electrode is worn out and the probe tip must be replaced.