The EGT probes do not come with a calibration sheet or chart.  They are a standard Type K thermocouple device whose output follows the ITS-90 Type K thermocouple linearization curve. Most modern day instrumentation can read a Type K thermocouple directly.  In some cases, thermocouple amplifiers are required to interface between the thermocouple & the particular measuring instrument.  But if you absolutely must have a calibration sheet then we can send the probe out to an independent agency who will issue us a 5 or 10 point Calibration Test Report that includes data.  There is an additional charge for this service.

Some customers will use copper wire to extend the cable, but please note that this can have a negative effect on accuracy of the temperature reading.
We recommend using thermocouple extension wire along with thermocouple connectors. The wire and connectors are made from specific materials that will ensure the best accuracy of the temperature reading.
You can find these products to build your own Extension Cable on our website at the following links:
Extension wire

Male Connector

Female Connector

Reducing the length of the EGT probe's wire by a few feet typically will not affect the operation or accuracy of the probe.

The maximum length you can extend the EGT probe's cable is about 50 feet.

All of our EGT probes output wires are isolated (ungrounded) from the probe's outer sheath

It sounds like the sensor's wires are hooked up backwards. Please confirm that the sensor's wiring to the meter input terminals is:
YELLOW = + (positive)
RED = - (negative)

One EGT probe placed in the collector will measure the leanest (hottest) running cylinder. For a quick test of which one that is you can do the following:
With a running engine, take an EGT probe & touch it to the outside of each pipe. Make sure that you are measuring at the same distance from the header pipe flange or manifold runner. Write down the temperature of each pipe. This will tell you which cylinder is running hottest.

Our EGT probes are designated “special limits of error” for +/- 2 degrees F (or +/- 0.4% range) accuracy tolerance.

EGT probes are our core business. Our products are manufactured in the USA and constructed from high quality materials. The exposed sensing tip MgO insulating material is flame hardened to stop powdering & embrittlement which can lead to failures of the sensing element. The probes' outer sheathing material is made from either Aerospace Alloy Inconel or 316 stainless steel depending on the application. Our EGT probes have water-resistant FEP insulated wires that will withstand up 500 °F (250°C). The cable's outer jacket is stainless over braided for maximum strength and abrasion resistance. All this adds up to one of the most affordable yet robust EGT probes available on the market.

Typically at the center of the exhaust stream.