How are TM-33 .xml documents (per ANSI/IES TM-33-18) with partial data sets (i.e., with photosynthetic photon intensity distribution data or spectral quantum distribution data, but not both) formatted?

TM-33 .xml documents required for Hort V3.0 submission must contain photosynthetic photon intensity distribution (PPID) data produced by goniophotometric testing (per ANSI/IES LM-79-19) and spectral quantum distribution data (SQD) data measured in an integrating sphere (per ANSI/IES LM-79-19). In most cases, both sets of measurement data must be included in a single TM-33 .xml document. However, in some cases (see the below FAQ), the data may be separated into two TM-33 .xml documents, referred to by the DLC as “TM-33 .xml documents with SQD or PPID data only”.

TM-33 .xml documents that only contain SQD data must contain the SpectralData and EmitterSpectral elements but should not include the AngleInterpolation, PhotonData and PhotonIntensity elements (example). All other required elements must be present.

TM-33 .xml documents that only contain PPID must contain the PhotonData and PhotonIntensity elements but should not include CustomData and its nested elements, the SpectralData and EmitterSpectral elements (example). All other required elements must be present.

When a TM-33 .xml document with only SQD or PPID data is uploaded to the TM-33 Horticultural Lighting Presubmission Tool, an image containing the corresponding data will be produced, and a warning will state that the other required data set must be submitted in a separate TM-33 .xml document.

Does the DLC accept TM-33 .xml documents (per ANSI/IES TM-33-18) with SQD or PPID data only (i.e., with photosynthetic photon intensity distribution data or spectral quantum distribution data, but not both)?

When testing a single model for SQD data and PPID data, submitted TM-33 .xml documents should contain both photosynthetic photon intensity distribution (PPID) data and spectral quantum distribution (SQD) data for ease of submission and review. However, the DLC will accept TM-33 documents with only SQD or PPID data when necessary. For example, separate TM-33 .xml documents will be accepted when testing is conducted in separate labs, and/or for Level 2 applications where separate model numbers are tested.

For level 2 applications, SQD data, measured in an integrating sphere (per ANSI/IES LM-79-19), is required for the models with the minimum photosynthetic photon flux and efficacy. PPID data (per ANSI/IES LM-79-19), produced by goniophotometric testing, is required for each unique optical and distribution pattern. If the model numbers used for producing SQD data and PPID data within a family are different, the data may be submitted in separate TM-33 .xml documents.

How does the DLC uses spectral radiant flux data in submitted ANSI/IES TM-33-18 .xml documents to create SQD images?

V3.0 of the DLC’s Horticultural Lighting Technical Requirements requires that full LM-79/SQD reports are accompanied by an ANSI/IES TM-33-18 document containing Spectral Data, along with other required elements. Submitters are required to use the DLCs Horticultural Lighting Pre-submission Tool to automatically generate PPID and SQD images from a submitted document.

Per the ANSI/IES TM-33-18 standard, spectral radiant flux data from the Spectral Data section of these documents is reported in units of watts per nanometer (W/nm). However, for horticultural applications, photosynthetic photon flux is commonly used, and therefore the spectral radiant flux data needs to be converted to units of micromoles per second per nanometer (µmol/s*nm). The DLCs Hort Pre-submission Tool generates SQDs by automatically converting the Spectral Data in W/nm to µmol/s*nm so that the generated SQD plots show photon flux on the Y axis.

The formula for converting between spectral radiant flux and photosynthetic photon flux is given below (source: ANSI/ASABE S640 (2017)).

where:

Φ_p is photon flux in units of µmol/s

Φ_λ(λ) is spectral radiant flux in units of W/nm

λ is wavelength in units of nm

N_A is Avogadro’s number, 6.022 × 10²³ photons per mole

h is Planck’s constant, 6.626 × 10^-34 J × s

c is the speed of light, 2.998 × 10⁸ m/s

When calculating spectral photon flux, the integral cancels out.

When constants are multiplied, the equation above simplifies to

where:

Φ_{p λ}(λ) is spectral photon flux in units of µmol/s*nm

Φ_λ(λ) is spectral radiant flux in units of W/nm

λ is wavelength in units of nm

The DLC uses the above formula to convert the spectral radiant flux data (in W/nm) given in the Spectral Data section of the ANSI/IES TM-33-18 .xml documents to spectral photon flux (in mmol/s*nm). Below is an example of this conversion, where spectral radiant flux is equal to 1 W/nm at each wavelength given.

This conversion is used by the Hort Pre-submission Tool to create SQD plots. Below is an example of a data set represented as an SPD with radiant flux (left), as it is given in the ANSI/IES TM-33-18 document, and the same data set represented as an SQD with photon flux (right), converted by the tool.