1. Produktet er slutview
The Extech PH90 Waterproof pH Meter is a precision instrument designed for accurate pH measurement across various applications, including water quality testing, hydroponics, aquaculture, swimming pools, beverage production, and laboratory use. This device features a robust waterproof housing, a replaceable electrode, 3-point automatic calibration, and auto buffer recognition for ease of use and reliable results. Its compact design makes it suitable for both field and professional environments.

Figure 1: Extech PH90 Waterproof pH Meter. This image shows the compact, handheld pH meter with its digital display and control buttons, ready for use.
2. Nøglefunktioner
- Reliable pH Testing: Provides quick and accurate pH measurements for various liquids and semi-solids.
- Bredt måleområde: Covers a full 0-14 pH range, suitable for diverse applications.
- Automatisk kalibrering: Features 3-point automatic calibration with auto buffer recognition for consistent accuracy.
- Holdbart og vandtæt design: Built to withstand wet conditions, ideal for fieldwork and outdoor use.
- Replaceable Electrode: Extends the device's lifespan and ensures long-term reliability.
- Klar LCD-skærm: Easy-to-read digital results, including pH and temperature, even in varying light conditions.
- Integrated Temperature Measurement: Built-in temperature sensor for accurate readings.
3. Opsætning og klargøring
3.1. Batteriinstallation
The PH90 meter requires two CR2032 Lithium Metal batteries (included). To install or replace batteries:
- Skru batteridækslet af, som er placeret øverst på måleren.
- Isæt de to CR2032-batterier, og sørg for at polerne vender korrekt (+/-).
- Skru batterirummets låg forsvarligt på plads igen.
3.2. Electrode Preparation
Before first use, and after storage, prepare the electrode:
- Remove the protective cap from the electrode tip. The cap contains a moist sponge to keep the electrode hydrated.
- Rinse the electrode tip thoroughly with distilled or deionized water. Do not wipe the electrode, as this can create static charges.
- Allow any excess water to drip off.
3.3. Indledende kalibrering
For optimal accuracy, perform a 3-point calibration before initial use and periodically thereafter. Calibration buffers (pH 4, 7, and 10) are sold separately.
- Tænd måleren ved at trykke på ON/OFF knap.
- Immerse the electrode into a pH 7.00 buffer solution.
- Tryk og hold på CAL button until "CAL" appears on the display. The meter will automatically recognize the buffer and calibrate.
- Skyl elektroden med destilleret vand.
- Repeat the process with pH 4.00 and pH 10.00 buffer solutions. The meter will automatically detect and calibrate to these points.
- Once calibration is complete, the meter will return to measurement mode.

Figure 2: Close-up of the Extech PH90 display and control buttons, including ON/OFF, MODE, and CAL buttons.
4. Betjeningsvejledning
4.1. At foretage en måling
- Sørg for, at måleren er kalibreret.
- Rinse the electrode with distilled water and gently shake off excess.
- Sæt elektrodespidsen ned iampopløsningen, og sørg for at sensoren er helt nedsænket.
- Gently stir the solution to ensure homogeneity and allow the reading to stabilize. This may take up to a minute, especially if the sample temperature differs significantly from the meter's previous environment.
- Read the pH value displayed on the LCD screen. The temperature will also be displayed.
- After measurement, rinse the electrode thoroughly with distilled water.
4.2. Hold-funktion
For at fryse den aktuelle aflæsning på displayet skal du trykke på HOLDE button (if available, typically integrated with MODE or a separate button). Press it again to release the hold and return to live measurement.
4.3. Automatic Temperature Compensation (ATC)
The Extech PH90 features Automatic Temperature Compensation, which adjusts pH readings based on the sample's temperature, ensuring accuracy across varying temperatures. The temperature is displayed alongside the pH value.
5. Vedligeholdelse
5.1. Electrode Care and Storage
Proper electrode care is crucial for maintaining accuracy and extending the life of your meter:
- Always keep the electrode tip moist. Store the meter with the protective cap filled with electrode storage solution or pH 7 buffer solution. Never store in distilled or deionized water, as this can deplete the electrode's electrolyte.
- Rinse the electrode thoroughly with distilled water after each use.
- If the electrode becomes dirty or readings are sluggish, clean it using a mild electrode cleaning solution. Follow the cleaning solution manufacturer's instructions.

Figure 3: Close-up of the Extech PH90's replaceable electrode tip, which requires proper care and storage.
5.2. Elektrodeudskiftning
The PH90 features a replaceable electrode. If the electrode performance degrades significantly despite proper cleaning and calibration, it may need replacement. Refer to the Extech webwebstedet eller kontakt kundesupport for information om købasing replacement electrodes (Part PH95).
5.3. Udskiftning af batteri
When the battery indicator appears on the display or the meter fails to power on, replace the two CR2032 Lithium Metal batteries as described in Section 3.1.
6. Fejlfinding
| Problem | Mulig årsag | Løsning |
|---|---|---|
| Unøjagtige eller ustabile aflæsninger |
|
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| Måleren tænder ikke |
|
|
| "CAL" error during calibration |
|
|
7. Specifikationer
| Parameter | Værdi |
|---|---|
| Modelnummer | PH90 |
| pH-interval | 0 til 14 pH |
| pH-nøjagtighed | ±0.01 pH |
| Temperaturområde | (Not explicitly stated, but integrated for ATC) |
| Strømkilde | 2 x CR2032 Lithium Metal batteries |
| Varens vægt | 2.88 ounce (ca. 81.6 gram) |
| Produktdimensioner | 6.7 x 1.4 x 1.4 tommer (ca. 17 x 3.6 x 3.6 cm) |
| Inkluderede komponenter | Flat surface pH electrode, cap, batteries (pH buffers sold separately) |
| Fabrikant | Extech |
8. Garanti og support
For warranty information, technical support, or to purchase replacement parts and accessories, please visit the official Extech website or contact Extech customer service. You can also find more information and products at the Extech-butik på Amazon.





