METTLER TOLEDO
 

 

Calibration Is Key
   
Measuring pH
   
Contamination Control
Does Your Meter Meet Your Need?

Temperature is a Critical Component

For Secure Results











SevenEasy™
Ideal for routine lab work
 
SevenMulti™
For regulated labs and those that require more advanced automation		 
Automatic Temperature Compensation (ATC)
 
Manual Temperature Compensation (MTC) 
Avoid Sensor Contamination with TRIS Buffers




















The right meter
Maximize accuracy and precision by choosing a meter that:
  • Has the appropriate error limits and measuring range for your applications
  • Allows a broad enough range of calibration points and calibration algorithm
  • Offers the correct level of security regarding user management, password protection etc.
  • Supports your compliance and automation needs

Find the most suitable meter for your needs at www.mt.com/pH
The right service solutions
Regular service will increase your meter’s accuracy and extend its life. METTLER TOLEDO offers many service options – tailored to your needs – to ensure that your meter perform reliably.

For perfect calibration results
  • Use fresh buffers
  • Apply the same stirring conditions as for the measurement itself
  • Choose the calibration standards that bracket the expected measuring range
  • Calibrate and measure at the same temperature

ATC works best with normal-size samples.
  • Use a sensor with integrated temperature probe and wait for a stable signal. The meter automatically corrects the pH signal. ATC works best in samples larger than 10 mL.
  • Any “Pro” type InLab® sensor – InLab® Micro Pro, Science Pro, Expert Pro – has integrated temperature probes, eliminating worries over wrong temperature settings or not capturing temperature.
  • For sensors without an integrated temperature probe, use a separate probe.

MTC is extremely accurate, but can be time-consuming.
  • If the temperature of your sample is known (you’re working in a climate-controlled room or the samples just came out of the refrigerator) enter this known temperature in the measuring settings of your instrument to correct the pH (or conductivity) signal.
  • When measuring samples with different temperatures, MTC can be time consuming, because the setting must be changed with every temperature change.

Accurate pH measurement is a key factor in buffer quality. TRIS-based buffers – widely used in biological research ranging from molecular biology to histology – can damage standard pH equipment.

How does TRIS do its damage?
When measuring pH during TRIS buffer preparation, the reference junction on conventional pH electrodes can clog when TRIS reacts with silver ions in the fill solution. This reaction can also occur with protein in the buffer, such as BSA.

The eventual result is slow or fluctuating readings, or even entirely wrong results.

InLab® electrodes by METTLER TOLEDO are specifically designed for compatibility with TRIS-based buffers, assuring reliable results and accurate buffer values. The electrolyte in InLab® electrodes is guaranteed to be free of silver ions, eliminating the possibility of contamination of the junction in TRIS or protein-containing buffers.

Let us assist you in finding your dream electrode!
www.electrodes.net



























Specific to conductivity
  • Use low conductivity standards like 10 or 84 μS/cm as quickly as possible – they react with CO2, which changes the value
  • Avoid electrostatic charges from the measurement vessel
  • Avoid bubbles in the probe

Specific to ISE (ion-selective electrodes)
  • Always use the correct ionic strength adjustment (ISA) solution – in the right concentration
  • Condition the ISE according to the operating instructions

Measure the sample, not your sensor.
With very small samples, the sensor can take so long to reach equilibrium that the sensor temperature is wrongly interpreted as the sample temperature. The sample mass is negligible compared with the sensor mass, so take the time necessary to ensure that you actually measure the sample temperature.

Keep your sensor with your sample.
Make sure temperatures match by storing the sensor with samples in the refrigerator or incubator, or at room temperature. This guarantees the highest accuracy because the pH membrane, reference system and sample are at the same temperature.

Clean with RNase and DNase cleansers and autoclave to eliminate biohazard
The pH electrode models InLab® Power, Power Pro, Viscous and Viscous Pro can be sterilized by autoclaving. By cleaning the sensor with RNase and DNase decontamination solutions first, the potential for biological contamination is significantly reduced.











Order your informative poster "pH Tips & Tricks"